Show a preference to Flow boots because they are designed to work best with Flow bindings. BUT, you need the boot that fits your foot best. Flow bindings depend on a good fitting boot first and foremost.
I took this approach, John. I bought Flow 'The One' boots (lace) because they're designed with heel cuts that better accommodate the high back without rubbing, and they're very stiff, great for use with the NXT-FR (which I still have, but don't think they make anymore). Mine were 2009, and I LOVED them. Super comfy, even with laces only had to tie 'em up once, rarely needed to readjust during the day. They had a one year warranty...halfway through my second season (out of warranty), the entire side seam on my back foot blew out. Separated about 4-5 inches. It was "hidden" inside the binding, so I was able to gorilla glue it closed, and the liner kept my foot warm. The repair would last for most of another day, then more glue. Sucks. I really liked them, but I just bought a new pair of Thirty Two Focus Boas...and haven't missed the flows at all since. The Focus is pretty low profile, but it still has a slightly more squared off heel, which doesn't fit the Flow bindings as well. I wish I could recommend the Flow boots, because they were awesome for one season. But $300 is a lot to spend just to throw them away after less than two seasons.