I actually got one of the original membrane ones. It's a bit quieter than the new mechanical ones, and $20 cheaper, and it's built with the same idea. I can attest that I can really type quite faster when I type on it, and it makes a very satisfying pounding noise.
No software came bundled with it, and I haven't had any luck with double command or adjusting keyboard shortcuts.
Brightness and volume are the two things that I would want too. Fortunately, one can control by default the brightness with the scroll-lock and pause keys, but I still haven't gotten volume.