Coming from a N1, I was skeptical about how much better my upgrade to a SGSII would be, especially because the N1 was so close to being a perfect phone (besides wonky multitouch and limited internal memory). Almost had the phone for a month now and I'm loving it. Here are my experiences so far:
- Battery life: The battery really impresses me, considering the horsepower of the phone and the size of the screen. Far outlasts my N1 (with extended battery) with it's smaller 3.7" screen. If I don't go crazy downloading apps and playing games, it will easily last me throughout the school/work day (9-9). No problems here.
- Screen: incredible clarity and color reproduction, and actually usable outdoors. Also, pixel density isn't an issue. Unless you're a troll and/or in a lab with a microscope, you shouldn't make out individual pixels. Multitouch is perfect.
- Yellow tint: Initially I had this on the left side of my screen (only visible when viewing a gray/white page), and this concerned me because I imported the phone with no warranty support. But it went away after updating to 2.3.4 KI4 from Kies. Yellow tint is gone and screen is now flawless.
- Wifi: Works flawlessly as well. no issues reconnecting after waking from sleep, and no issues transitioning from cellular data to wifi. Might be a little hard on the battery though, but probably because faster internet = more usage from me. confounding factor?
- Misc.: Happy it works with my old AT&T Medianet plan (unlimited internet + tethering for $15) so saving a lot of money there. Some Samsung enhancements are good (smart dialing, swipe to call/text, uninstall apps from app drawer). Performance is crazy good.
Downsides:
- Touchwiz. Hated it at first, now it's almost unnoticeable. Not that bad, however manually having to arrange apps in the app drawer (you can only alphabetically order if you're in list view, or if you root) is annoying. Also I'm not a fan of the lockscreen at all (give me back my sliders!) Other than that, it does make up in some places where android lacks features.
- No notification light: Back then on the N1, the trackball notification lighting was amazing, especially after putting CM7 on it and being able to customize colors. Missing the notification lights a lot on the GS2. Tried noled and it's not for me, probably will use BLN when i get around to rooting and whatnot.
All in all, I love this phone. Nothing but compliments from friends, haven't been able to get the phone out of my girlfriend's hands. Even had a coworker decide against getting the iphone 4s after playing with the GS2. And of course I like it
Hope this helps!