The choice between the membrane and mechanical gaming keyboard should be based on what you need from your keyboard. If your primary use is gaming or spending lots of time typing work, you should use a mechanical board.
The feedback on mechanical keyboards is fantastic and much better than the membrane. But the mechanical keyboard is also a little bit noisy and more expensive than the membrane keyboard. The mechanical keyboard offers a much smoother typing and/or gaming experience thanks to the support for full key rollover.
If you’re on a budget or you’re planning on typing only every once in a while, a membrane is a way to go. The membrane gaming keyboard is more affordable and still provides a good typing experience, although the lack of key rollover makes them poor choices if you type fast or play games (FPS games).