Yeah I've read that over a a few times. I guess I should ask a few questions about it though. (Apparently I failed to notice that you were the person who made that thread, and was posting in my thread.)
Now you say that the 650s have less bass and high end than the 750s, but you say that if you like bass heavy music then you would be better of with the 650s. Although I do like bass, I don't like it when it distracts from the rest of the frequencies. I've had this problem with my current setup, as the bass on my Q40s will easily overpower the rest of the music sometimes. Moreover my E5 certainly isn't helping, as the main thing it does is add to the bass, even with the extra bass switch off. I can definitely deal with nice amounts of bass though, and even if I couldn't for whatever reason the left-most slider on the EQ always helps that out.

What about the 550s? They were only quickly noted.
Also, apparently RMC audio is quite near to where I live, and they seem to not only be the only place within a 100 mile radius that would carry ultrasones, but they also seem to be the cheapest place to buy them. I read something about PRO 900s for 300 some odd USD, I can't seem to find it now though. In any case I should probably take a trip out there and audition some stuff. But I've read that the ultrasones need a LOT of burn in before they sound good. Since I doubt that the cans that I audition will be burnt in, how will this affect the sound?