I'll check out some Unions at the local stores this weekend and see what I like.
Never saw the Switchback's before...kinda like Nike ID...I like the concept.
If you're going to be spending a lot of time in the park hitting jibs then jump on the contact. That's the go to for a lot of park guys on Union. The Force is a pretty burly all mountain binding, that will be a fair bit stiffer than the contact. A buddy of mine rides for a local shop and he's got the GNU Park Pickle and paired it with some Forces... he absolutely loves it.
I'm more of an Atlas guy myself. I put in a fair number of days every year, most of them in the park. It's Rices go to as well. You pay a bit more of a premium, but well worth it IMO. Both the bindings I mentioned will allow you're board to flex fairly true underfoot, without any deadzones, especially the contact.