There are some ways to improve VM performance. You could try to pre-create the disk volume instead of leaving it dynamic as it usually is, attach a partition directly, or move it to a different disk that'll not interfere with your other apps (my bigger home box has system and apps on one disk, VM volumes and network shares on another). If you do that, your performance hit for disk IO will be very close to zero. A modern CPU will usually not eat up more than 3% per virtualisation layer (at least under KVM). Beyond that, you can assign more cores to the virtual machine and see how it goes. Even a relatively humble i7 laptop has enough power to run Visual Studio with dignity for all but the craziest projects.

If we are talking about a beefy Xeon E5 workstation with 64 gigs of memory, you'll probably be able to assign more resources to the Windows VM than Visual Studio knows how to deal with.