I couldn't quite go for the 60%, but I have friends with the UHK60 and I really liked it as a keyboard.
I popped for the 80 as soon as the shipping times caught up to real time. It's a fantastic keyboard. I haven't gotten any of the clusters for it yet, but I'm very happy with my purchase.
I have the UHK 60 and I really like it, except as you mentioned no function keys.
The software is pretty good, includes a little DSL and you can do pretty much anything you want.