To be specific, Mer runs on the Q5, yes. (As mentioned and discussed throughout much of this thread.) The Q7 is, I guess, still kind of experimental, and there are no released images for it.

If the only thing annoying you about the N800 is the "small" 4" screen and/or poor video performance, the Q5 and Q7 could be the solution, but in some ways they're a step back. No d-pad is one of the big things people are getting excited about (and definitely the biggest problem for me), and the bigger screens (particularly 7") could easily support way more pixels, so the smartQs don't look so hot from here. I'm also an N810 hardware-keyboard convert, so it'd be a bit annoying going back to soft-keyboard only, but no deal-breaker.

Still, the price and capabilities are impressive, and if you're after a bigger screen at the same resolution, or more performance, why not?