On the Pronto, I would say there are roughly 10-15 different key screen patterns in which keys can be deleted accordingly. I think each screen could average 10-12 buttons. Any key can be taught any discrete IR code (within learn freq.) And as far as icons go, the Pronto has 48 available. So lets see here, thats 120 digits base 48.... but hey that's not including 96 upper/lower case chars....do I hear 120 base 144..... :)
I definitely like that wheel on the HK but i think some of it's hard buttons cannot be reconfigured. The Pronto allows reprogramming of all 7 hard keys, but i think the HK may have a better designed 'hard key interface'. This supports my initial premise that the Pronto seems to lean more towards true touchscreen and HK more towards conventional remote, as far as using hard keys a little more.
I don't buy that the HK is more customizable though.....regardless I think in the end, each with full-blown software support and periodic software upgrades will make either one a sound choice. Deciding factor may come down to personal prefs in ergonomics more than anything.