I have still Poser 6 installed but I haven't used the last three weeks. I'm only using 7 now. I did had some problems but if you know some do and the don'ts it works perfectly.
 I love the render speed even with my single-core computer, the seperate render thread improves it even more, you only have to take care that you have enough virtual memory, I allocated too litlle and that caused some renderproblems but after I enlarged it, it ran super.
The seperate runtime handling is much better than P6, I'm thinking to set up seperate runtimes for every figure.
I've been working a lot with the cloth-room, I heard that some people had troubles with it, but there is one thing you have to avoid and that's cancelling a simulation. When you do, close poser  (after saving of course) and start over again, otherwise the program freezes.
There one thing I hate: Poser7. never gives a warning on renderingproblems, when something goes wrong, it does need improvement on error-checking. I like something as: you don't enough virtual memory or similar, now it just stops without giving any reason.

-How can you improve things when you don't make mistakes?