You've already hinted at possible reasons for not wanting to use stock Android, so really all I would say to elaborate on my earlier assertion would be that Ubuntu Tablet would theoretically provide a more ethical and potentially customisable out-of-the-box OS for my N7
... but if I found myself with time one weekend, yeah, I'd probably just mess around with Cyanogen.
I'd definitely consider using this if it were in a usable state
... I tried an early alpha version nearly a year ago and it was much worse than what you describe, so at least by the sounds of it they've made inroads since then. What with all the attention Linux gaming has been getting on the desktop, and knowing how big-an industry gaming is now, it'll be interesting to see if any developers turn their attentions to getting games out for Ubuntu on mobile processing architectures.