I've been using the HHKB for over a year now as my "daily driver" and I absolutely love it:
* I like the feeling of the keys, and also the compactness of the keyboard layout
* I like that it connects to both my work & personal laptops over bluetooth, and I can switch between them with a single key chord
* I like that I can carry the keyboard with me to the office, and that it was simple for me to take it with me on my recent trip to Australia, so I have my preferred keyboard feeling / layout wherever I go.
Before that I was using a Unicomp Model M as my "daily driver", and while I liked it, I don't really miss the extra keys.