[General Questions and Answers] -=Vex=-:
Well, here's my personal experience with both devices. I believe there's also still a topic I started hidden somewhere on the forums here when I was to decide wether to go with the SGSII, Sensation (XE) or wait for the Galaxy Nexus.

Now I'm in the possession of both the SGSII and the Sensation XE, so I pretty much have the best of both worlds. Down here is a quick overview of my personal experiences and a conclusion to why I'm using my current device (the Sensation XE).

Samsung Galaxy SII - International White Edition

At first glance it seemed like a great phone, small in design and a dedicated home button which can also wake up your phone instead of having to pry around with a power button alone. However, after holding it in my hands entirely set up with the battery in it, the weight was just way to low. I actually had to check my pockets regularly just to see if I was still in the possession of my phone. Now, I can see why people would like that, but the fact that the phone is so light comes with a price.

The durability of the phone seems to be abysmal. After inserting the battery and the simcard+MicroSD I had to put the back cover back on. That went according to plan, but suddenly I felt that the back cover wasn't matching up with the phone's housing anymore. There was a slight bulge where you have to insert your fingernail to remove the back cover which annoyed me to no end. After that, I decided to get a cover for my phone so it would stop annoying me, which it did.

Then the next issue arose with the hardware of the phone. The home button started to wiggle around a bit. no biggie I guessed, and just kept using the phone as it was. After a week or 2, a cracking noise came from the home button. Seeing as I hardly use the home button, it kind of surprised me, and I decided to think of it as a way to "crack in the device" like a new pair of shoes. Regardless, after a few more days of moderately to heavily using the phone, the cracking noise only got worse, and I decided to return the phone.

The replacement phone immediately suffered the same issue with the back cover, but with my case around it, it wasn't noticable, but the thought of knowing that it's there still annoyed me. Also, I had lost faith in the home button and tried to avoid using it as much as possible, so I only used the power button on the right side to wake my phone etc. After a while, the power button started failing to wake up my phone and I was forced to use my home button once again.

As far as software goes, the standard TouchWiz interface which comes with the phone is a immense piece of ****, excuse my language. I cannot tell you enough how much I hated it. Regardless, this is all up to personal preference, but it lagged for me at times, and only a complete reboot of the phone would restore a bit of fluidity.

The screen however is amazing. Regardless of the fact that the colors are over saturated to an extreme, the pictures and browsing I did seemed clear as day. No issues whatsoever with it. The only gripe I had with the screen was its resolution. at a 480x800 resolution, text would often appear jagged around the edges and not as sharp as I would have liked it to be. Even installling the Roboto font which is specifically made for text clarity, couldn't take away the roughness of the letters.

That's when I decided to start looking into custom roms, rooting and kernels. After trying out a multitude of roms, ranging from the golden oldies which have had quite some development time behind them to the recently released ones, the only rom which made my SGSII feel as it should be was Cyanogenmod. I must say that I was impressed by the fluidity of it. Regardless, I had to give up certain hardware acceleration options just to get a more fluid phone, which is not how it was intended in my opinion. This resulted in my feeling ripped off by Samsung.

However, the benchmark scores on the customised SGSII were out of this world. once you OC the processor to it's max and run a few benchies, you'll be quite impressed by what the device is capable of. However, in day to day use, it's impossible to keep overclocking it without having an immense amount of additional batteries stowed away in your bag, which brings me to my last point.

Before I chose to go to the Android side, I used to own an i4. Yes I know, bad choice and glad I'm back on the Android side after a year. However, the i4's battery life was simply amazing compared to the SGSII. The SGSII would not last me close to a days worth of work and I often had to recharge in the middle of the day. Note: This occured even with underclocking the processor, turning Wi-fi off and all the battery saving things which have been mentioned here on XDA. Whereas I was offended by the i4 that the battery didn't last me 2 days of moderate use (some games, browsing, video's and heavy music usage) the SGSII just left me baffled over the abysmal results it was producing. This is no different on the Sensation, but more on that in my second segment.

TLDR: Plastic device with rather bad production quality with hardware failures all around on 2 seperate devices. Great screen for colors, not so great for text. Battery life leaves much to be desired and fluidity of the device could most certainly be a lot better. A definite featherweight though, and if that's your thing, this is the ideal phone.

HTC Sensation XE Edition

The hardware on the phone is simply phenomenal. The aluminium finish really makes a difference in both style and quality. The fact that the entire frame is replacable is definitely a plus for when you accidentally drop your phone and the panel is scratched. The outside was definitely hard to remove the first time, but after inserting the battery, simcard and SD card, I didn't need to reopen the device again. Once closed up the construction still feels very solid without any mishaps on production quality. The weight of the phone is a lot more as how I like it and the rounded edges make it a lot easier to hold in my hands compared to both the i4 and the sgsII with their sharper edges.

As far as the hardware goes, people have reported both light leakages and dust under the screen, but I did not experience any of those issues on my Sensation XE. The screen is still dust free after 2 months of usage, and there is no light leakage whatsoever. I inspected the device for light leakage in a dark room under my blanket with the screen on and off for an extended period of time. The softkey buttons respond well and the volume rocker is solid as I like it. The power button is slightly more inconveniently placed, but nothing to fret about.

As far as the software goes. The Sense 3.0 interface which comes standard with the phone really makes this phone as special as it is. Unable to be ported to any other manufactureres devices, Sense provided me with sleek visuals while remaining to give me a fluid experience with the device. Ever so often the device would soft-reset itself because it runs out of memory though. Which could be seen as an annoyance at start, but hasn't happened to me after the first week for some odd reason. The Sense overlay really made my like this phone, and I have since then looked upon all previous devices I owned as inferior when it comes to their individual overlays.

The screen, standing at a qHD resolution of 960x540 which is simply great. Not astounishingly great, but it simply is wonderful. While I've always been sceptic about resolution differences on phones it has become more than apparant to me that even this tiny resolution difference on this 4.3'' screen makes a huge difference. Text is sharper, images are sharper and the overall experience is far more enjoyable. Not only when browsing, but while looking at videos and pictures as well. The colors aren't quite as vibrant as on the SGSII, but that's not something I'm actually missing. There have been talks about the screen having washed out colors at certain angles, but please, at the angles where the colors start washing out, you won't be using your device anyway.

The modding community for the Sensation seems to be quite equal to the SGSII's community, but there's one difference. The Sensation mod community seems to be a much nicer bunch compared to the SGSII, keep in mind that this is a subjective view, and should not be taken as a fact. After S-off'ing the device, rooting and installing custom roms, it's hard to stick with one certain rom while thre is so much to choose from here. Ranging from the standard Sensation roms to the XE roms and kernels, there's plenty to mess around with.

The battery life however, oh oh oh HTC, you failed there. You made an excellent device and then simply mess it all up with the battery. At first I wasn't able to get through an afternoon with the device. But that was mostly thanks to my "honeymoon" period with the device where I tried to exert its every resource. After installing a couple of different kernels and roms, I've managed to get up to 16 hours of battery out of the phone, which is more than acceptable. Keep in mind though that you might want to consider getting an extended battery.

TLDR: Great build quality with a good weight attached to it. Sense overlay really is a + for me, and the higher resolution screen definitely helps the Sensation in its presentational value. The battery life and lesser amount of ram shouldn't have been there on the flagship device, but when looking at the device in it's entirety, I must say that this is the least of my worries. Definitely a worthy device.

Conclusion:

I love my Senny, the form factor and android overlay simply made this phone into my favorite phone so far. It has also refilled my trust in HTC and its products after the failure which was the G1. I currently only use my SGSII as a backup device for when my battery dies on my Senny and is pretty much used as data storage whenever not in use, as that's all what its good for in my opinion.

Do take my opinion with a grain of salt, as I'm currently quite favorable towards the Sensation XE which I own. Nonetheless both devices have their ups and downs, but the upsides of the SGSII do not outweigh the failures.

Excuse this long wall of text and the lack of english grammar, I'm not a native speaker and I'm sure there are plenty of mistakes in here!

Regards,

Vex