By catering do you mean the food or the service? I don't think I've been to an away match recently where it hasn't been almost impossible to get served - so the Amex no different in that respect. And the food compares very well to other clubs' offerings (compare Piglets' pies to the horrible...
These articles are all subjective. The Amex came 6th overall in another recent survey. To put the London stadium 10th is risible. And the Amex should surely rank higher than 12th for design.