I agree that the food in Crown Lounge should be improved.
But AMS, is a very efficient terminal, shopping is not as good as T5, but unlike T5 it has nice restaurants, and many spaces to relax and play. Beside that, AMS Areas are different between schengen and non-schengen, with each section has a different interior design, which for me is very refreshing. With that + AMS’ efficiency, AMS is way better than T5.
Long walk? Sometimes, but you can always use the walkers, having said that, after a long flight, a nice long walk to the next flight is very desirable and a must for me, as it is very healthy. 🙂
One thing I need to clarify, FlyingBlue redemption, weak? I am sorry, but on basis of that alone, I can say with confident that you haven’t log-in to your account for a long time. And perhaps, your judgment of redemption availability is based on your experience years ago?
FB redemption is the easiest I have encounter and on their website on top of AF/KLM flight redemptions, FB website allows me to redeem miles on any SkyTeam flights from any point in the world. Also their availability is 95% on both long and short hauls in Y and J.