Are you C or Y? IMHO, AF C is way better than KL C, while KL Y is better than AF Y (since you have access to Economy Comfort and the food is slightly better).

Other than this, why do you want to add the extra segment CDG-AMS? It can give you some extra XP but is it worth the hassle?

IMHO (again) transfers at AMS do not compare with transfers at CDG due to consistency (as previous poster mentioned, docking at M gates at CDG implies you will have to walk enough to get to the train that will get you to 2F gates and that is only after you clear security and passport control). Some people find CDG is better than AMS for transfers, dunno, maybe they are AF/CDG die-hards. In your case, transferring at AMS would only require walking to your gate (prob. in the D pier).