I bought a couple of Model M keyboards on eBay a few years ago, however I haven't been using them simply because they are very loud! Now that I'm living in the basement, alone, in Cambridge, the loud noise isn't an issue. I actually like the fact that I can clearly hear an audible response for each and every key that I press. It also sounds pretty cool when I'm typing fast and all you hear is non-stop clicking. 🙂
My specific model is rather rare and hard to find -- one of the original keyboards, part number 1391401. I'm a huge fan of durable things so it's awesome to be typing on a keyboard that was made when computers, like the one I'm using right now, cost over $1,000,000 (if they even existed). How's that for cool!