[Samsung Galaxy Nexus] JC0406:
After finally getting the update, I tried 4.2 for the first time. To be honest, I imagined 4.2 to be a needed update to the already amazing 4.1.2.

PERFORMANCE

Like some of the users have stated, there is a slight slow down in performance. After using 4.1, the drop in frame rates in 4.2 is more evident. Apps run slower, laggier, and less smooth. Not all apps though, just some. To name a few would be Apex Launcher, Lock Screen App, Whatsapp (only slightly) and a few others. This bugs me. Project Butter? I definitely do not feel that its faster now despite what people have said.

STABILITY

I don't know how many apps I couldn't run because they forced close. And I'm suspecting its due to this 4.2 update. So now I'm patiently waiting for the updates to hopefully solve the problem.

NEW FEATURES

- Lock screen

I really dislike the new lock screen. It just looks ugly to me. The fonts they used in 4.1 was already great. Why change it to this? Google Now has been placed down at the bottom now, making it slower to access it in my opinion. There were a few times where the phone couldn't detect my swipes - maybe it could just be my fault for not hitting the right place). The idea of having widgets on the lock screen is well...rather niche. There isn't even a lot of widgets that can be added on to the lock screen unless I have to reinstall all my apps that I installed before the update. The worst thing about is, it lags. Even on the lock screen.

- Quick settings menu

I don't really find this helpful. Here's why. I already have an app called 'Notification Toggle' that basically adds toggles in my notification bar. Its minimal, quick and fast. I have no problem with Google adding their own version. Its just that in doing that, they have gotten rid of the settings button at the main notification drawer (one finger pull for notifications). Their own toggles are alright. I'm OK with the look of it, but 5 toggles just isn't enough for me (the others are just shortcuts e.g. settings, profile, battery). Hope Google puts back their settings button like in 4.1 or just improve on their toggles.

- Photosphere

One of the main updates in 4.2. I do like the software and layout behind it. Its really well thought out and its definitely an improvement from 4.1.I can access things faster, capture pictures faster and do photosphere - which is googles new 360 panorama that is similar to Google maps Street View. It isn't exactly perfect but I'm guessing its also the users part to take a well-stitched photosphere.

- Keyboard

This is probably the part where I won't complain. This keyboard is the keyboard I've been waiting for. After using Sense 4's keyboard with 'Swype' gestures, I couldn't find any keyboard that could outmatch it. Everything was perfect for me with that keyboard. But now finally I can say that I have found a better one. Not only aesthetically but also functionally. I type faster and smarter now. Google has done a great job with the prediction engine. Almost 90% of the time I'll get the word I want. And even if I don't, the word will more than likely to appear next to the main predicted word. But I believe that the upcoming updates will improve on that.

CONCLUSION

And no, if you're wondering I'm no apple guy. I prefer Android over iOS. These tiny little things just tick me off sometimes. Especially when it comes to performance issues. Most probably either jumping back to 4.1 or flashing another ROM. I think the only thing I wanted from this update was the 'new' keyboard and probably photosphere. I could've just got it separately and not complain. But anyway, that's my thoughts on 4.2. Quite disappointed as you can tell. If you're thinking of updating, think again before you do.

UPDATE: Replaced lock screen with Widget Locker. One problem down. Weird, but it seems a tad faster now for some reason. Battery life is about the same or maybe a little worse.