If you think AA is flooded with elites, check out the Delta forum and ask the Diamond Medallions how they are doing with upgrades (spoiler: a lot worse than us on AA). I'm a Plat and with some strategic booking, I've been upgraded roughly 75% of the time this year. As a Gold at Delta, I'd be likely to snag Comfort+ even when flying off-peak. Yeah, Delta has the seat-back screens and SkyClub access with my AMEX plat, but if I am just going to sit in economy 95% of the time I'd rather just fly Jetblue and sit in MCE (which is, in my opinion, the best economy seat in America).