First off, I waited for the OTA. After rooting/romming the heck out of my previous phones (OG Droid and Droid X) I decided to let this one sit stock until the OTA dropped. It was a tough wait. Mainly I was tired of having to go back to stock to get the phone ready for an OTA. Easy, but tedious.
My number one issue with my Nexus was the 3g/4g hand off. I live on the fringe of 4g coverage and I work in the heart of it. With 4g enabled, my phone throughout the course of the day would spend 15-20+ % of the time without a signal. When it lost a signal it would take up to 3 minutes to get one back. If I disabled 4g, I would go all day with 0-3% of the time with no signal. Fine it works, but I paid for 4g.
Also, my #2 problem was battery heat and drain. I assume, could be wrong, that with my phone running so hot it prematurely drained the battery. This seemed to be caused by the hand off issue of 3g/4g, and the Android OS, which over the course of the day would always end up #1 in the battery drain. Regularly my phone would "idle" in the high 80's low 90's. If I was streaming iHeartRadio and surfing the web it would regularly get to 100-105.
Both of these issues seem fixed for me.
I fully charged and then fully discharged the battery first. The first full charge lasted 15 hours with minimal to moderate useage. That is with 4g enabled, and that whole time, 15 hours, I had 1-2% without a signal.
All day yesterday, initial charge, and today, second full charge my battery has yet to hit 90 degrees. It is idling in the high 70's and working in the mid 80's. Right now, I'm 6 hours into today's charge. I am at 54% battery left. #1 usage is the screen at 45%, #2 is phone idle at 18%, #3 is cell standby at 15% (0% w/o a signal 4g enabled all day), #4 is Android OS at 5%, tied with Mediaserver at 5%.
That's the top 1 or 2 things I've noticed. Huge improvement in 3g/4g, battery temp and life.
What have you guys seen?