C_Servboth bindings are hit and miss. if you are like a lot of skiers, you are looking for the most bang for your buck. FKS definitely will help you to prevent from hurting you legs and knees, but it seems like that comes with a price (Durability). But, the FKS is far more light then the griffon. With the griffon, you do have more bulk and weight, but the binding should last you much longer. both range in price from 250-300$ (depending on what year and where you buy from). in my opinion, griffon is the way to go.
You have no idea what you're talking about.
FKS are not really any safer for your legs and knees. They may be considered safer because they will prevent inadvertent releases (that you do not want on a steep face in dangerous terrain) on various hits because their elasticity will absorb the jarring without ejecting the boot. This has been debated on here a lot though, I'm not going to go into it.
FKS is a way more burly binding than the Marker griffon-(almost all plastic). The problem with FKS is the brakes themselves have a flaw/issue with bending or breaking when you eject switch. The binding itself is probably the most bombproof out there. They are also heavier than other alpine bindings at 1100 grams for the FKS 140, and 1250g for the FKS 180- the griffon is one of the lighter ones on the market at ~1000 grams.
Basically, everything you said is wrong. So please keep your mouth shut unless you actually know what you are saying.