Yeah but unfortunately it wouldn't make any difference with an extra stick. Sega did have a twin stick joypad driver coded at one point I believe but they never released any hardware for it.
As for FPS games, sticking with mouse and Keyboard is hands down the best way to play them. I have both of them and playing all of the awesome Half-Life mods in glorious 480p on my 43 inch plasma Pioneer is quite the sight.
Anyways it matters not to me that this has no analog stick on it at all. I got this to be a unique rare alternative to the ASCII fight pads.
The total control plus adapters would be good too but I really like the simply clean plug in nature of it no daisy chaining a controller to an adapter. Also, it would be nice to fit the innards of this into a real PSX pad shell.
I bet with some slight modifications the controller PCB would fit like a glove into it sans the turbo keys.