I want to start out by saying that I absolutely love P.E. I ran it on my OG exclusively, and I've been running it on my GNex since you guys started back up. It is by far the smoothest, fasted, most stable ROM out there. Thanks for all of the work that goes into this.
I've been running the 11/15/2012 build as my daily driver, and just flashed the 1/18 build. One thing that I noticed was that wifi reception dropped considerably. Prior to flashing, I had full signal, but after flashing, I have one line, sometimes barely two (this is sitting in the same spot on the couch). I also noticed that my signal indicators, both wifi and cell go grey fairly often. During the restore of my apps, wifi quit all together, the phone rebooted, and I needed to restore everything by hand. Not really that big of a deal.
I'm still not sure I like some of the 4.2 changes. The pinch-to-zoom camera isn't my favorite. I like the zoom bar (or better, volume rocker zoom). But I don't generally use the stock camera, so I'm not too disappointed in it.
The system is incredibly responsive. The graphics are smooth and quick, and the build over all seems rock solid. I don't see myself going to any other ROM.