Performance -
Like the QuickFire Rapid we put the full sized QuickFire Pro through about 10 hours of gaming. This was with a variety of games from Alan Wake to Mass Effect 3 and through some older (but no less fun) games like Bioshock 2 and HalfLife 2. We have to be honest here, the QuickFire Pro felt a little nicer than the Rapid. Between the non-slip surface and the feel of the Cherry MX Brown switches it was simply better feeling. The movements were very precise and while the throw of the keys seems longer there was no need to hammer on the keys to get them to respond. The backlighting was also a nice touch. We did some gaming with the lights out. While we know the layout of a QWRTY keyboard by heart and do not really have to look at it the lighting was nice and made of finding the right keys easy in the dark.
The rubber feet also kept the QuickFire Pro in place which is a plus for many gamers, I know we have often pushed our keyboard around the desktop and have to stop to put it back. With the weight and the sturdy feet the QuickFire Pro stayed in place.