Would depend. AF can be quite unfriendly/unhelpful on the ground, KLM are usually better. If you misconnect on a through ticket, they should be able to sort you out, but AF can be a little bit deficient in this regard. The rule of thumb for AF/KLM is that if you combined AF in the air with KLM on the ground you'd actually have a pretty good airline.
I do like AF in the air though. I've only flown A340, but it had good food. Haven't flown BA in Y for ages to compare though...