I've seen similar problems, although I haven't tried every new feature.  Mysterious crashes where P7 just vanishes.

I was in the setup room deleting bones to setup a a clothing set and ... gone.

Opened V4, applied a high res mat and one of the eye surfaces is opaque.  Can't see one of the eyes. Renders fine, but rather annoying to look at while working.  Doesn't happen in P6.  And I have repeated it several times with the same results.

On the other hand, the new mesh morphing tool seemed to work ok. It's handy to directly modify the mesh from within Poser.