ORD is such a left behind outstation for a lot of airlines that it almost doesn't matter if you have lounge access or not as it either just as good or better in the actual terminal. I dont know if that is due to the United strength there or what, but ORD and 'lounge' are not two words I really put together.
Hoping that all the ORD construction means that BA will eventually have access to the AA Flagship lounge (only just reopened a few months ago), which I think is the strategy BA are taking at other large AA hubs (like Dallas). Or at the very least a decent lounge in T5.
But at least your onboard experience sounds like it was worth it!