BA has recently (and finally, after years of cuts under Alex Cruz) upgraded their PE dining, both in quality and appearance. On a round trip LAX-LHR recently, I found the food to be on par with AA's, and it is also served in ceramic tableware now. (Though on ORD it may be only the first meal, I know the shorter flights have a more abbreviated second service.)

OP mentions they are OW emerald, but for anyone who isn't a sapphire or above, AA would be the logical choice because of free advance seat selection.