X-keys programmable keypad

As a left handed gamer who mouses with my left hand I am always looking for alternatives to make up for not being able to use WASD comfortably. I use the numpad for most games but mmo's and the like are not great for that since you need access to more keys than you can reach on that side of the keyboard. I have tried a few game pads but most are contoured for righties. I would love to see a mouse like the Naga for lefties but I don't think that will happen anytime soon.

Anyways, tonight I found this:

It is a large 58 key programmable key pad. You can get different size keys for it, colored keys and spacers to set it up however you want.

It looks like it would solve a lot of my keyboard problems. It does not however look to be very durable.

Has anyone had any experience with one of these? I would like to know how tough they are. Are they as responsive as a keyboard? How well do they handle multiple key presses at a time and holding one key in for an extended period?