MunkySpunk

I rock the K2 Cinch's too, they're a bit heavier than normal bindings, but once you've got them dialed in, you'll never have to sit down again. I like them better than the Flows b/c they have a real strap setup even though the Flows are lighter. They're nice and snug although its 'hybrid' toe strap that's supposed to function as a toe cup or traditional toe strap sucks as a toe cup, pops up every time you wipe out from toeside.

Oh, and your board is going to probably be a bit more sluggish than you're used to (although a brand new Gnu 161 might weighs less than a 10 year old Burton 152.. dunno). But it'll hold an edge MUCH better than your Burton b/c it's edges are razor sharp, it's stiffer, and longer. Carve away.

Edit: And the move from Burton (or any) SI to a real strapped-in boot is going to be like night and day. I'd say any difficulties you meet in getting used to a longer board will be WAY more than offset by the benefit losing the SI's. You're going to feel like someone spot-welded your feet to the board.