Problems I've had with P7 are:
1/ Throwing me out to the desktop after a render without the chance of saving the work.
2/ Random crashing.
3/ Always defaults to 72dpi even when 300dpi is set.
4/ Delete not working properly.
5/ Selective render does not work at all, I just get a black screen.
6/ Workspace is very sluggish even on a fast PC.

All of the above problems are a pain but I live in hope that these issues will be fixed :)