Got my phone on the 15th and loving it. 
But then, this is a huge upgrade from OG Droid that I had.
The battery life for me is great (so far). With the OG Droid, I couldn't get cell phone signal at my work desk at all (picture one of those who are holding their cell phone in the air and going around in circles trying to obtain some sort of cell phone signal to make a call) and the wi-fi signal continually went in and out as well. With the Nexus, I've noticed much improved wi-fi signal (the location of where the wireless routers are placed at work could also have contributed to the variance in signal on my old phone, though).
At work, I only use my phone to listen to Pandora and with wifi off, battery only decreased by 25% in an 8 hour work day. Factor in text messaging (a lot) and accessing the web as well, it drops to 50%. I haven't tried watching Netflix on it yet. Battery has been good so far with wi-fi.
4G service is OK. It's great in the places that I need it, except for at home. Signal drops to 3G as soon as I enter our neighborhood. Wi-fi compensates for that.
The only issues I've encountered are:
1. Extreme touch sensitivity while using the native keyboard. I type quite fast and instead of recognizing the letter I want, it will choose the keys below, above, and next to it. (my fingers aren't an issue because they are slim and small - female over here) It drove me crazy since I really didn't want to bother adjusting the settings. However, now that Swype beta is available for ICS, problem has been solved.
2. Volume (which is a given). I never used the vibrate option (annoying), but I have to with this phone to get notified of any calls or texts along with the notification sounds at max. I'm hoping 4.0.3 will fix it (crossing fingers!)
3. Picture quality. I don't take pictures much, but when I do, I still have to take several in a row to get the best one that is actually in focus (auto focus doesn't work as well, even after tapping several times) and in the right lighting.
4. One major issue I've started to notice is that when I'm typing, no text comes on the screen. The only fix is a reboot. I thought it was just only for the stock keyboard, but i installed Swift Key and encountered the same issue and it just happened with Swype today. Not sure if this is an isolated issue. If so, the unit can be replaced with a working one.
5. As with others, the slow battery charge is problematic. If I leave work and it's at 50%, although it's on the car charger, by the time I pull into my driveway, it's only gone up by 10% with a 20-25 minute drive. For it to be fully charged, I've got to keep it on the charger for another 4 hours without any type of activity.
Buut, despite the above, I'm enjoying my new phone and haven't had to "customize" it at all - yet.
