Depends on what ya measuring. The fact that food service in the US in non-existant is not really the FA's fault - and they've been 'brought up' in an environment where taking 1hr+ to do a drinks round is the norm.
Granted British FA's are more likely to be younger, so if you want to base the judging on looks, fine, hand all the prizes to Ryanair, but with a out of the ordinary query, say something like customs or immigration rules, connecting gate locations, etc., I'd guess the older more experienced 'average' Amserican FA will be more likely to know the answer.
All based on observations as a SLF.
WT
<Fly CO 767>