The main selling point of the HHKB is the layout, not the switch. And you can't ignore the layout once you've bought it, right? Have a close look at it online and see if you're interested in learning it. Realforce have ordinary layouts (only a couple modifier keys are narrower than on your garden-variety Windows keyboard).
The HH aren't only very small, they're reasonably light and portable. Realforce aren't huge either, but they're seriously heavy ****ers, easily double the weight, not something you'll enjoy lugging around every day if that's a consideration. On the other hand, of course they have a very solid feel on the desk, if you like that.
Thanks to the layout and form factor, an HH is an instant conversation piece for anyone who walks in. A Realforce (especially the lightless 86U) looks unassuming and is only a conversation piece for people who care about keyboards.
Resale value shouldn't be that bad, if you find yourself with buyer's remorse for either.
Ideally, of course, you would borrow one from somebody nearby for a week and see how it serves. Even a HH Lite should be interesting, for the layout.