From someone who has always given preference to AF over KL on all aspects, I must say that the Dutch have really nailed it with the Premium Comfort. Seat, food, service. Everything is at least two steps ahead of AF, especially if you are on their old product.

However, the non Schengen lounge in AMS is a complete zoo in comparison to the AF lounges in T2E(concourses K,L,M). If you have a long layover, then this makes it worthwhile rethinking what is otherwise an obvious choice in KL's favor.