Originally Posted by 321liftoff
I was considering moving away from AA/US to NW and VS. I fly to the Midwest a lot, and NW has the best schedules and the most full-sized jets. I also think that VS would make for a great airline across the pond, especially with premium economy, and its ideal use on a daytime flight. However, looking at it, I think I should credit all miles to CO. I can earn/redeem these on all three airlines, and this way I will be able to use one set of elite credentials on all, and requalify more easily since all travel will go to a single account. Would it still make sense to use a CO account in this case, or is there something I'm missing?
You're missing the fact that standard award seat availability on CO is atrocious. Award availability is very poor for U.S. domestic tickets and near impossible for business/first class overseas. Unless things have changed, I believe that using miles to Europe on Fridays and Saturdays during summer months is not permitted.
Before making the change, do yourself a favor and directly compare standard award seat availability for AA (or US, where applicable) and CO on routes you would consider redeeming miles on. A smattering of random dates will suffice. You will likely see a huge difference.