OP, I recently faced a similar choice. I had a TBolt for over a year that I had rooted and flashed like crazy and was running perfectly, but it developed a hardware issue where it stopped taking a full charge.
I mined the forums and while it seemed there were more bugs with the GNEX than the RAZR, I went with a GNEX for the clean Android experience.
So far I have been very happy.
ICS is legit, I like the new unified Google look and so far all the software aspects are very satisfactory. On my Bolt I mostly ran AOSP rom's and if that is your thing then ICS will make you very happy. I may not even root this one because it does everything I need it to stock and there is almost no bloatware.
Battery life is good but not great. Running 4g all day, which includes two subway trips and working in a steel and brick building with crap reception will burn the phone down to about 15% by the time I get home. If I run 3g all day gives me about 50-60% by the day's end. On heavier usage days I'll usually hit it with a 1/2 hour charge at lunch and I have a charge well until I go to bed. Also I have left it overnight without draining.
No dropped calls, no data issues.
Screen is sick, but heavy bright screen usage can eat battery pretty damn fast. This is probably my biggest issue with the phone.
Sound in the headphones is good, no screeching, sounds better and seems louder than my Thunderbolt with a Beats rom.
Only other minor issue I had was that it didn't recognize my amazon mp3's at first and it was a little annoying to move my pics and other SD stuff over, but I have rapidly gotten past that.
Maybe I'm just blown over from coming from the notoriously buggy TBolt, but the GNEX has made me very happy.
I hope you enjoy whichever phone you pick.