I had FKS last year, and they worked great. My only complaint is that they were a bit annoying because you sometimes had to re-position the heel piece if it swiveled sideways.
I'm liking the Marker griffons on my new setup this year. they feel solid, and release very predictably. Not to mention they a a bit lighter than the beastly FKS. I only weigh 150 lbs though so Griffons work fine for my 9 DIN setting. I'd say if you're over 170lbs though, and charge hard, get some quality binders like the Jesters, Jester Pros, FKS 180, or salomon 9-16 (Atomic FFG team 16s)