Its been a pretty good 13+ months with my N4. At first I went through all the rooting and unlocking but then found that the only benefit to me was being able to change the colour intensity on the screen. The downside of rooting was certain banking and finance apps wouldn't work so I've been back to stock for the past 9 months or so. No regrets. I am running ART however.
Phone still works smooth and I've never had the random reboots like other have mentioned. Not to my knowledge anyway.
The only thing I've noticed is recently the Snapdragon battery app has stated my charged battery life is now around 42 hours when it was around 60 a month or so ago. Who knows.
Going forward my main concern Nexus phone wise is that they become phablets. I would dearly love the Nexus 6 (whatever) to go back to a 4.7" design. I am not a fan of humungo phones.
Facebook
Twitter
Instagram