I just wish Parallels would fix the issues plaguing version 10 of the software. Looks like they'll just roll the fixes into Parallels 11 and sell me an upgrade.
Interesting thing is that last night, I tried to install the Win 10 Enterprise Preview via Parallels and the install went great up until the point that it was finally ready to boot to the Win 10 desktop and then it threw an error saying that one of the Parallels drivers wasn't signed properly and that I had to repair the install.
There was no option to continue so I was simply SOL. The Parallels "Support" team (I use that term loosely) told me to try rolling back to a previous snapshot of the VM. When I replied that I didn't have any snapshots since I had just installed the OS, their response was that they're working with Microsoft to try to find the cause of the problem. I told them that it seems pretty cut and dry that one of their drivers isn't signed properly. I'm sure that problem will be fixed with Parallels 11 but who knows if they'll leave Parallels 10 out in the cold or not?
Also, full screen VMs on external monitors, while supported, have been broken since at least version 10.1.2. It used to be that if you powered down a VM that had been full screen on an external monitor, closed Parallels, reopened Parallels, and launched that VM again, it would automatically return to full screen on the external monitor it had been on when it was closed. Ever since 10.1.2, whenever I launch a VM that had been full screen on my external monitor, it launches full screen on my MacBook display and I have to shrink it down, drag it over to one of my two external monitors, and make it full screen again.
I reported that problem months ago, they acknowledged the problem, but still have yet to fix it. Once again, it will probably be fixed in version 11.0, which I'll have to pay for.