Hi, interesting poll and request.
I'm still on ICS (stock based superleggera v7) and I tried a couple of KK ROMs, but I had to revert to ICS because of very bad battery life. Even using tasker and greenify to limit battery drain my ray did not survive for an entire day (1 phone call, some SMS and IM, an hour of browsing/rss/pocket).
Also some application were not so responsive, but I think it was because of too aggressive tasker/greenify settings.
Too bad because I wanted to try how google now (and uber!) would fit in my daily usage... But maybe it's time to buy a more recent phone!