There are two things I know of that make a gaming keyboard a nice thing. One, programmable macro keys. Makes life easier in some cases, or if you really get into it its downright cheaty. (I only ever used ot for an event in one game that wanted you to mash space repeatedly... pain in the ass, so I put autofire space on one of the keys.)
The second is that the ones I know of guarantee that multiple keys pressed at once will register. (The one I got a while back guaranteed five.)
When I built my old gaming rig I just purchased a back-lit keyboard that was wired. Just grabbed the cheapest one that fit those two things (Yeah yeah, didn't need the back-light, but it was pretty. sue me)
It didn't work so well playing games since you could not press W, Shift, and Space simultaneously. It would only register the first two pressed, and ignore whichever was third.
Made playing first person games rather difficult since many have those keys bound as forward, sprint, and jump.
Gave that keyboard to my uncle, since he doesn't' game at all, and purchased myself the gaming one I mentioned above.
Currently I'm using a laptop, and sometimes I get the same thing in Mass Effect 3 multiplayer. (Old gaming rig is dead, so yeah)
The X key doesn't like to register whenever a few other keys in the WASD area are pressed, so when I use an ability bound to that key I just had to learn to let go of all other buttons and then press the key. That is obviously not a good solution, but its workable.
So depending on the keyboard, and the specific key bindings involved, you may find yourself having unrecognized input. You don't have to worry about that with the "gaming" keyboards I've read up on.
Oh, and I guess the fact that most gaming keyboards are back-lit and you can customize the colors in nice, but there are some non-gaming ones that have the same. Or at least there were last time I looked. Been a few years since I payed any mind.