After my foray into the world of IBM Model M keyboards, followed by a few months using the impressive Microsoft Natural Ergo 4000 I eventually came to the conclusion that the Model M was the better keyboard of the two. The tactile response of the Model M is unmatched on any keyboard I've ever used, however the lack of Windows keys (and misbehaving Shift key - that was one old keyboard!) was a real pain in the ass.
I was anxious to try out two keyboards: the elitist Das Keyboard (the original version - there was no Das Keyboard II at the time) and the Unicomp Customizer, which is based on the original Model M technology. The possibility of a brand new Model M with Windows keys was simply too difficult to pass up and I opted for a black, 104-key USB Customizer (which looks wicked cool, check out the image on the right!)
Although I've only been using this keyboard for a few hours I can safely say that it's the best keyboard I've ever used. The tactile response is simply astounding -- basically everything I've said before about the Model M is equally true for this keyboard. Unfortunately this also includes the fact that it's a very large keyboard, which can sometimes mean too large; the finger travel for some of the keystrokes is a little much for my really small fingers (particularly when I have to right-shift or use one of the function keys). I guess the best thing ever would be a Microsoft Natural-style ergonomic keyboard with buckling spring keys (a la Model M). Maybe even one with blank caps... one can only hope 
As an aside, the Israeli tax is murder. Aside from exorbitant shipping price (not PCKeyboard's fault, it's just the way things are...), the Israeli customs laws dicatate a 15.5% VAT on every package whose value is higher than $50 (the tax can be higher, depending on the content), but they include shipping in the tax calculation!