Overall, I'd give the FKS a 9/10 simply because it's not all-metal. The plastic toepiece, while certainly not flimsy, is no match for a metal racing-type toe.
The performance of the FKS is top-notch, you will never find a better binding. It has a shorter mounting zone than most other bindings, meaning a more natural ski flex.
Release pattern: Second to none. The Pivot/FKS has stayed the same for over 40 years for a reason, it's the most consistent, reliable binding you can buy. It has a turntable heel that rotates under the heel (as opposed to behind it or not at all) and this leads to a more natural release pattern. I can set my bindings at the lowest possible setting (5 as opposed to my normal 8) and not pre-release, this says something.
The FKS 140 has a metal heel, and the heel is pretty much indestructible. I have seen 40 year old pairs kicking around, good as new.