The boot isn't noticably faster without. It didn't really fuck up the multiboot per se, though I was unable to mount the ntfs volumes in linux without rebooting into Windows 10 first. What I hate is that when you choose Windows 7 from the win 10 boot menu, it reboots and then loads windows 7, instead of just proceeding to load it. Anyway that it works at all is a minor miracle. So far I'm liking Windows 10 pretty well.