I have never had the chance to ride any Lib Tech boards or gnu bindings so I can't say anything there. The Heritage is a solid board, and giving you are going to be doing mostly carving around with skiers, it is a great board for that. It's also great in the back country.
I haven't tried the new flow design, and I used to be a huge flow fan. But lately, I just don't like the feel of their bindings compared to the more traditional style. They seem to be stiff in areas that should flex, and soft in areas that shouldn't. I also always had trouble with the forward lean adjustment. It is a a little screw, that slowly tightens the cable. In bumpy terrain, I find myself having to re-adjust several times a day because it loosens. This happened to me even on the more expensive nxt-atse model.
Anyway, have fun riding with a bunch of gapers all day.