Sorry, I don't know a ton about Flows... The thing that always scared me about Flows is taking a spill in some POW and having to dig yourself out just to be able to unstrap and walk if needed.... They only seem to come in handy if your riding with a group of other with Flows, or riding alone. If your with a group and your the only one without Flows, then you're waiting on everyone else to strap in anyways.
But ya, sorry I don't have any advice on which Flow is a good one... I've had Burton Custom bindings which I loved, and I know have Ride NRc which are brand new and havn't even been put on my stick yet.