AS has had a good relationship with DL for the past several years, ever since NW joined SkyTeam. They codeshare extensively with DL, and do not compete on many routes.

Of the partnerships that AS has, CO is probably the shakiest domestically. They don't offer many reciprocal benefits and they compete with CO on EWR, IAH and ANC routes. However, like AS's flight to MSP, these also serve as feeder flights to codeshares.

I actually wouldn't be surprised to see AS continue their partnership with CO, though. They are happy to partner with any airline where such partnerships make business sense, and they aren't a member of any alliances.

Yeah, this was another point I forgot about - indeed very annoying. However, I was somehow pretty sure it was an ST rule of some sort and that it will change in *A.

Don't bet on it. There are plenty of fares in *A that have partial (or zero) earning depending on the program and the partner.

Ive flown US only a couple of times with carry-on only. they werent terrible but glad they arent my reg carrier.

just finished 30k on UA, got a Match from my CO Plat and was given PE (their Gold) thusly I was able to enter the Lounges on my Intl trip and all segments on both my SYD and HNL trips were reserved in E+, along with next weeks trip to TLV via IAD (LH from/to FRA and TLV). But a heck of alot better then COs Y product

From what I saw Id say COs FC domestic is better then UAs FC (other then the PS flights). Intl with UAs new config they win out over COs BF

So Id say CO Y over USs Y, USs FC over COs Y and UAs FC and E+ over COs product and USs as well