I tend not to use it, but I have had good experiences with it. For virtual surround, it's highly dependent on the virtualization algorithm, so there are good and bad implementations. The best I've heard thus far is Waves NX. I combined Waves NX with a Stax Lambda-series headphone (which already has an interesting "frontal" soundstage) to play an orchestral piece and it was possibly one of the best "out-of-head" sound experiences I've had. The Waves NX Windows desktop app has been discontinued though.