I dont play any games that require me to use F keys. I used to be a sponsored[vVv, steelseries, alienware] L4D player, i went to WCG in 2003 & 2004 for Wc3 TFT.
But back then i was using a razer lycosa & Sateik eclipse 2 keyboards.
The games i play with my HHKP2 are: Tribes Ascend, Dota 2, Minecraft, counter strike, Wakfu, TF2, Killing floor, Soldat, And soon to be diablo 3 & BF3 with my new rig. The HHKP2 is not bad for gaming AT ALL. The capactive switches have been the fastest actuation switches i've ever used while playing dota 2. It's just unreal how i can't even bat an eye with this board and i get a full spell combo off. A bigger upside is the alt/control spots are much better placed for FPS as well. On my old keyboards i always made my crouch my shift because it was easier to use then control. Now the HHKP2 lets you make the 2 keys next to the space bar ALTS, Control is right next to A, and shift right under with tab in easy access for cycling through units in RTS games. Although, The only RTS i really play anymore is Dota 2 which doesn't require a full array of keys like SC2/WoW demand. Which i still see no problem using this board at all with unless you need F keys.
In the time i was gaming with my deck mx clears, it felt so weird to play FPS games with the keys since you always bottom out, and once you get past the tac bump on the clears they get heavy as hell so i just started hovering over the tac bump. After switching to a small form factor keyboard i dont see any normal sized spaced keyboard being good for many games at all to be honest.
The small spacing of many keyboards like the poker, noppopo, pure, race, HHKP2 etc, all have a very solid design for the short space of keys and the ease of access to getting as many keys as possible. If you NEED f keys the best board for gaming would be a noppopo layout board with mx red, brown, or ergo clears.
Either way, i have no problem gaming with my HHKP2 and it's a huge pleasure gaming with it. Although, it would be 10x better for gaming if they made a HHKP2 with 30g weighted keys. Sooner then later i'm probably going to get a KBT Chase /w cherry mx red switches just for gaming, since it has a nopoppo design and it's pretty much perfect for all games. I'm on the fence about the pure though too. I figure if im going to want a cool looking board with a massive selection of switches and backlighting i'm gonna have to have at least one cherry board. It sucks sitting here not being able to customize my HHKB the way i want to.