So I did this yesterday, downloaded the jar and ran it on the commandline using nohup.  Eventually will probably add it into the p2pool startup script so it's all handled automatically.  Logfile shows decent transaction activity.

Since server restart just over 24 hours ago, my efficiency hasn't dipped below 110% (that I've seen), and is currently hitting 114.5% ... .  31 shares, 1 orphan, no dead.  

Previously I was bouncing between 95-105%, lately a little under 100% a bit with about a 14% share loss.

So, we'll see how this runs over time... if it keeps up the way it is, then it's a big thumbs up in my book.

EDIT - although it seems to be a bit of a resource hog - 11G of virt RAM according to top.  Then again that could be just usual Java bloat and not necessarily this program since it really isn't much.