I have both and compared to a more traditional binding (Salmon STH, Rossignol Axial, etc...) they're both a B!T#H to get into in deep powder... but as stated above it isn't that big of an issue... I mean if you're good enough to need Griffons/FKS you're definitely good enough to snap into them in snow...
Obviously the FKS is a much more durable binding than the Griffon... but the griffon is also half the price. I think you'll be really happy with either.