A few things to consider.
1. The Gnu Mutant is a terrific binding. It is even better this year with larger more fully releasable ratchets.
2. It is a tricky comparison between a Flow Flight 2 at $149.00 and a Gnu Mutant at $289.00. $140.00 in a binding buys you a lot of extra performance! A nylon baseplate and basic surf strap will not offer nearly the lateral control of aluminum and one of the higher end straps.
3. This is Flow's first year doing a toe cap.
I'm not even sure they were Flight 2s. I just remember I didn't like their non-toe cap design and found them harder on entry than the Gnu Mutants. $400 Flow bindings with the same over-all design would still have had the same problems.
I love my Gnu Mutants and have been very happy with my choice. The fiance is very happy that she isn't waiting for me at the top of the hill. She still waits at the bottom, but she did that anyway when I skied too. She's even faster now that she bought a men's high performance all mountain expert ski (Rossi Strato 70 TLDs). She loves me even more after I convinced her to demo them and then buy them. Demo ski price ridden one other time by another expert. Right length for her. Good deal on those babies.
I could straight line it and she'd almost beat me down the mountain. Damn is she fast.