Any particular reason you have a Windows host + linux VM instead of the other way around ? Personal experience has been Linux hosts + Windows VM performs better than the other way around.
Windows handles media much better than linux. I have a linux media server as well, and while I like it for somethings, getting Blu-Ray/DVD/MP3/CD/Netflix/etc. working in it is not one of those things. Windows just works in that sense. Also games, although this is more of a theoretical bonus as I rarely play anything.
I virtualize Linux under Windows too. My primary reason is gaming. I can use Linux without any hardware acceleration. My dev environment is entirely virtual and there are advantages to being able to throw it on a thumb drive and carry it around. Or I can be staying with a friend for a week and setup my ideal working environment on their computer in a few commands. Another advantage is it's much smaller than a Windows VM so I can store more Linux VM's/snapshots on my puny SSD.