I just qualified for mvp75k or whatever it is for 90k partner miles. Flew a total of 600 miles on AS metal this year. Most of that was biz international trips on BA or DL or AA with the occasional domestic flight when I couldnt fly UA. If I was flying coach international a lot I would consolidate on one airline but if you're paying for higher fares on a mix of airlines then crediting to AS is a good deal, and the 50k bonus miles are really nice. The one time I flew AS I really loved it but being in Texas it isn't real convenient for me. If you're premier Gold on UA I'm going to guess you don't get a tons of upgrades going through and since the international upgrades you only get with UA 1K are not a factor then I would encourage a switch. I don't know what you would miss from your UA days.