If you're on a Mac or *nix, and/or you're fine with learning a 2nd layer for things like arrows and ins/del/home/end/pgup/pgdn/etc... then go with HHKB. I personally think it's a better pure typing experience than the RealForce boards.
If however you can't give up the standard 87-key layout, the RF is the way to go. As far as switch weight, see sig for preference.