When it comes to gaming, you only need NKRO if you're the kinda dude that shuns the wasd layout. Basically, if you're a wsad fan, and use modifiers like ctrl, alt, and shift for ducking, crouching, etc, you probably don't need NKRO.
If you prefer something like rfdg for movement, or you play operation flashpoint-type combat sims, racing sims, etc which have tons of commands that you need to use whilst running and such... NKRO can come in really handy.
I don't game much any more, but those are my thoughts.