I HATE them. It has been a long time since using them, but they were all in 2006 and older CEs. The "tone" just clashed with my amp rig. I don't remember specifics other than there were weird frequencies that I couldn't dial out. In fact, it was pretty much that pickup combo that kept me away from PRS for years.
Same hereI don't wanna say I HATE the HFS, but if I bought a PRS with one in the bridge it would be coming out. It came out at a time when hair metal and hard rock were king and it is really meant to hit the front end of an amp hard or drive a signal through a long chain of effects/rack gear.
It does what it is supposed to do for sure: it is hot, tight, clear and very bright. It always sounded shrill to my ears and had a hard, unpleasant way it interacted with my playing style. I disliked the Seymour Duncan Custom for many of the same reasons. For the "high output" PRS pickups, I think the Tremonti and Metal are both much better and the Dragon 1 as well.