I'm coming from a Samsung Moment (2.2), but I've also used the Nexus S a bunch for work. Overall I think the phone is great and I'm happy with my purchase, assuming there is a fix for my first con.
Cons:
- Games crash randomly. I think it may be a bug related to how sound effects are played. The games I've tried are Tetris, Doodle Fit, and Plants vs. Zombies. For a while PvZ seemed ok when I turned off all sounds, but I had it crash twice in a row last night.
If anyone is able to play the games I've mentioned with no crashing I'd be interested to hear it, since it may mean that I have defective hardware, but I've seen similar crash reports about the Galaxy SII.
- Keyboard is junk in my opinion. Fortunately there's a free 2.3 keyboard on the market that works well.
- Touchwiz is meh. It's not terrible, but I much prefer stock Android.
- It notifies me to unplug the charger when it is full charged. There is no way to turn this notification off. Why?
- The vibrate notification is always the same (long vibration), so I can't tell if a notification is a phone call until I wait for the 2nd vibration or I look at the screen. On my Moment, phone calls had a long vibration while everything else had shorter vibrations, and I liked that. I don't see any way to customize these.
- A little too big for me I think. I have normal sized hands for a 5'11" guy, and it can be difficult to reach parts of the screen with my thumb when I'm using the phone with one hand.
Pros:
- Screen is beautiful. I don't find myself caring about the resolution.
- Really fast and responsive.
- Even 3g data feels faster, due to the phone being fast overall (compared to my old Samsung Moment, so might not be saying much). No data lockups or anything so far. The only time I even bother turning on 4g is for app updates.
- Battery life seems pretty good.
- GPS is really quick, haven't had a problem yet.
- The 'Wi-Fi / BT / GPS / Vibration / 4g" controls in the toolbar are really useful (not sure if this is specific to this device, I haven't seen it before).
- I like how thin and light the phone is. You barely know it's there when it's in your pocket.