As do I, and that's what I had in mind, actually. Being able devote several testing VMs instead of just one host workstation is very appealing. As is the easy availability of snapshots that can easily be discarded in the event that a bug causes the VM to become unresponsive.
Eventually, of course, DEs have to be tested on hardware, but much testing can be accomplished before it ever comes to that. Not to mention, tests can easily be done on distros other than Solus, where Budgie might be offered as well.