For those thinking of upgrading to Pro, note this response by Parallels to a user on Twitter (of course they wouldn't bother coming to their own forum to answer it):
https://twitter.com/ParallelsMac/status/634084075389759488
So you could spend $99.99 and a year later end up with software that has been disabled and is completely useless ... so it's basically a software rental only ...
Q: I own v10. If I now buy a Pro subscription I can use v11. What is AFTER that year if I don't subscribe again. Continue on 11?
A: your installation will stop working when you no longer subscribe.
A: your installation will stop working when you no longer subscribe.
https://twitter.com/ParallelsMac/status/634084075389759488
So you could spend $99.99 and a year later end up with software that has been disabled and is completely useless ... so it's basically a software rental only ...