I think that those of us who use Parallels when we need to use Windows programs and do not use a lot of secondary and free programs will not have problems with this installation. I had zero problems upgrading. The installation and updating process took foooorever but worked well. Unlike some, I find that the system launching and program launching are quite fast. The convergence presentation takes a bit of getting used to but I quickly learned to like it, even though I tend to keep related programs segregated in Spaces.

I do not use it a lot but I must for some Windows only tasks. I can only say good job Parallels for a very useful Mac friendly program. I will defer my comments on various program installations in Windows before I comment further.