When I fly out of NY and have to connect via IAH I almost exclusively fly out of LGA (instead of EWR). EUA's on this route are incredibly sporadic and impossible to tell. I'm generally on 433 on Monday afternoon and I've seen this flight go out with empty seats in F one week and then the next I'm in back.

The super early 530am flight (did they stop that one?) and the last flight back in (leaves IAH at 655, so you get supper!) are generally solid on upgrades. I think I'm batting 100 on those.