I upgraded from Poser 7 about a week ago and for me it was very well worth it, although not bugfree, it's much more stable. The library's search function is something I really really miss every time I open Poser 7. Now I know a lot of people say you can get a search function using an external library manager, but I prefer to have things built in instead of relying (and spending money) on external applications.

I like the interface a lot more too, docking pannels allow me to have just what I need, and have more workspace overall.

The render engine, even tough is 32 bits, is faster than Poser Pro, at least on my experience, but I've seen a lot of people say the same here.