[Xperia SP Q&A, Help & Troubleshooting] donk165:
Thanks for the advice, For me, its the lack of RAM on this phone which is my problem. After a reboot, i have about 300mb free ram, and as soon as I have more than one simple app running (or just one game), ill get a very slow UI, and I have to be very careful and patient with it or it will crash. To me, that is terrible, why would anyone think this is acceptable for a smartphone to just about be able to run an app and hold the interface together. When the System UI crashes, or the lockscreen, It frustrates me so much! The most important part of a touchscreen phone is the UI, without it, your just staring at a blank screen.

There has to be something deep in this phone (the kernel?) where its memory management is broken in someway, ive never experienced a phone be so unstable with 1GB of RAM. When I bought it, I was really hopeful it would be good, it was higher specced than my last phone, it had 4g, it had jelly bean updates coming out, and at the time, a future update to kitkat, and we had support from FXP and CM. What weve actually got is a half baked attempt at 4.3 by Sony, a cancelled 4.4 update, and weve been moved to legacy support by FXP when CM11 didnt even get to the stable point. We may have lollipop builds coming out which could be the savior for this phone, but im sick of waiting for something which might not happen. I just want to be able to rely on my phone and not spend half my screen on time waiting for something to crash and then restart.

Back on my Optimus L9, it has only 768MB ram and a lower clocked dual core CPU but that could run CM10 fine, I never ever had UI crashes, ever! I got lag from time to time, but nothing crashed. Thie SP has 100mb+ more RAM available and a higher clocked CPU but it feels so much more clunky and unstable compared to the L9, it should be the other way round. On my nexus 7 2012 which is similarly specced to the SP (apart from the tegra quad CPU) I again, had no UI crashes, I had lags, but at least things didnt crash. My friend has the Xperia L, which is lower specced than the SP and is only on 4.1, but again, he never gets UI crashes and generally, his phone can run games smoother than I can even though he has lower specs!

This phone, for me, just doesn't fit my needs. It cant really multi task how I would expect it to, and having the phone pretty much lock up if its writing to internal storage is a joke, installing an app from the play store, and not being able to bring down the notification bar to look at the progress without causing problems, to me just feels like something is seriously wrong. The lightbar was the only thing ive really liked on the phone to this day. At first, I was loving this phone, it was great, the only problem I had on 4.1 was that I couldn't play Injustice because it would close the game after a while. I thought, ill wait for software updates, hopefully Sony will fix it. Then the 4.3 updates came but they were buggy, but I held onto hope because at the time, 4.4 was in the pipeline. Then we got a few more 4.3 updates which did fix some bugs but this RAM problem was still there. So I gave up on Official software and tried out custom stuff. I've tried modified Stock ROM's where you get more features but the same inherent problems are there. Ive tried CM, but there hasnt been a stable release of 4.4 and the snapshot builds have also stopped. Vanir ROM is designed to be stable, its one of their highest priorities with their builds. And I definitely feel the difference, but this lack of RAM becomes more obvious with time, this week, I've seen my UI crash 4 times.

Ive done what you've said about fully starting fresh with PC companion Ive flashed stock FTF's and Ive done the PC companion method, Ive done that at least 5 times in the past. When I first do it, it seems like everything is okay. But without fail, after a month of use (usually less) the phone will bog down and the RAM issues return. Maybe my specific device has faulty RAM or something or maybe the storage is messed up. All I know is, this phone has not been enjoyable for me to use, lower specced phones are out performing it, and its value has plummeted in trade in stores like CEX, my old L9 that I traded into my local CEX is being sold for more money than an SP is.

Im sorry to rant but ive just had enough of this phone.

Ive got to flash the phone fully back to stock for when I sell it, so ill go back to full stock, and see if it will last.