I just tried my new Unicomp Spacesaver on Day of Defeat: Source and Age of Empires 2.
On FPSs, the Buckling Spring is just average. I have nowhere near the same control as I do with my Deck Legend which is a Black Switch. The response is poor when you move around, IMO. I don't even think it is as good as a rubberdome for FPSs. The click does nothing. Despite that, I still got a lot of kills.
On the RTS, it did fine. But for moving around the map, again, the black switch was better. Quicker and more responsive. Many people like the blue switches because of the click you get which is good for RTSs so you know when the item/unit has been chosen. But for me it didn't really do anything. I listen to the sounds in the game to tell me what I've selected. I like the way my Deck feels when queuing unites. Lots of control.
So for me the Black Switch is the best keyboard on the market for gaming. It is perfect. I have never tried any other color, though. Buckling Springs are amazing for typing. Probably the best.