So I just opened and have been playing with my brand new Matias Tactile Pro Limited Edition Silver & Black and I must add that it arrived a lot faster than I expected!
And now just my own quick thoughts as I type on it:
In my opinion the build quality is fine. The silver paint job isn't spectacular (and not in a bad way, just that it's quite obvious that it is not aluminum) but it matches quite well with my MacBook Pro's aluminum casing which is, I assume, similar to the casing on my iMac at work. It is similar to the color of the plastic found on the silver keys of the pre-2008/unibody models of MacBook Pros, not exactly but close. I personally like the color scheme as I was never a fan of Apple's white keyboards anyway and I found them to get dirty quite easily, especially the keys. Also, I must add that with the back feet extended, the left side in particular seems to slide around a bit but seems to be fine when they aren't.
I absolutely love the feel so far and beginning to enjoy the click-clacking sound of the keys but I can see the latter being annoying to my neighboring coworkers (fortunately most of them wear earphones/headsets). But I'll be bringing it to the office tomorrow to give it a test run and see what the general consensus is... The keys do 'ping' a bit but seriously, it's not that bad and if it bothers you that much I think you're better off finding a completely different switch.
I do love the keyboard and the only thing I can say at the moment is that I wish there were more media keys (specifically: previous, play/pause, and next). I also don't particularly like all the extra legends printed on the keys since I've memorized the ones that I frequently use but I see the benefits of them to the general audience and overall I am entirely happy with the purchase. I've only been playing with this thing for the last 20-30 minutes and I really haven't explored it much so I'll probably have more to add later.