I bought a GFS Crusader and a Vintage '59 (bridge) a couple of weeks ago from the Guitar Fetish Yahoo store. I'm very pleased with the result.
I put the Crusader in the bridge of my Carvin Bolt kit. In there it gets some nice and chunky metal tones but, unlike some other high-output humbuckers I've tried, it also has an upper mid spike that helps it cut through well (ie it doesn't go muddy). It also sounds good split where it takes on sort of a hot-midrangy single coil sound, sort of like the SD QuarterPound.
I put the Vintage '59 in the bridge of my Ibanez Artcore Talman along with a SD Seth Lover in the neck. (The stock ceramic Ibanez ACH humbuckers weren't very good.) Putting these two pickups in the guitar really helped it out a lot. They work together really well. The Seth Lover has a little more bite to it but that may be due to it not being potted where the GFS is. Comparing the build quality of the Seth Lover to the Vintage '59 you could see a little more attention to detail on the Seth but I don't think that it would affect the sound quality that much.