Tried it a few times, not enough to really get the full flavour of it because i allways go back to sandboxie for testing(familiarity and all that)
One thing it is good for is seeing what an application does, i.e. reg entries/changes folders and that.
The paid version has a lot more pre-configured rules set up for internet facing apps, there is a way of getting the free similar but not here
It is 7/Vista compatible so that`s a good start(with UAC on).
Home page =
http://gentlesecurity.com/