J TATL service is mostly back to normal on AFKL.

You will find some differences on the hard product, AF J seats are almost completely full-aisle-access+lie-flat, whereas KLM still flies an awful lot of 2-2-2 J cabins on their 777s.
I also find food&beverage to be sensibly nicer on AF than KL, be it on the ground or at the departure lounge.

Then, of course, is the question of price, availability, and flight schedule convenience for which your situation is unique