RF switches are metal-plate mounted. HHKB Pro 2 switches are case mounted. This feature alone does not necessarily make the RF of higher quality. The two mountings are just different; one is not necessarily superior to the other. However, this factor may make the RF feel more solid to the user than the HHKB Pro 2.
I favor the HHKB Pro 2 for its following qualities: unique and efficient layout, form factor, symmetry, styling, dye-sublimated PBT keycaps, and Topre switches.
I use various other keyboards as well, but I like the HHKB Pro 2 layout so much that I remap my other keyboards to the extent possible to the HHKB Pro 2 layout.
Having said all this, although I am reasonably satisfied with the HHKB Pro 2 as it is, if I could change some things, I would ask for the following: metal plate, 55g Topre or capacitive buckling spring switches, complete programmability, and possibly a Bluetooth option.
My current daily driver is an IBM XT keyboard with Soarer's converter, remapped to a hybrid Mac-HHKB layout, and retrofitted with a detachable USB cable.