Priority check in already doesn't mean much with online/mr.chicken available. At least domestically. Priority boarding is nice for overhead space, but moving 2P to zone 2 would still allow that. Fewer elite warm&fuzzies though, and I doubt they'll do that. Upgrades, at least out of SFO, were something I never saw as a 2P... and I can't imagine it's gotten better in the years since then. I agree with jef7... it's all about the E+ these days, so I wouldn't go much out of my way at all to get from GM to 2P.