I know a bit about the VT program. I'd say that it really depends on what you want to do, and what groups you're interested in. VT at least, is a pretty big program, so there are a lot of people to work with, the downside is that it's a pretty big program, and funding pressure can be uneven across the department.
As for more prosaic pros and cons, Blacksburg's actually not that great, if you're not into college football or drinking, there's not a whole lot around, and it's a long way to anything (including the airport).