Originally Posted by
Kalboz
I'd convert these to SPG and then on to SQ - 485K SQ miles can get you two RT tickets in Biz or better anywhere SQ flies.
Forget about AS or UA where the availability is really miserable and hotel rooms can always be had at a discount.
Star Alliance availability with UA miles is actually pretty good, compared to most other programs. Not my favorite airline in the world, but availability in and of itself isn't usually the issue for me. I've found it quite a bit better than AA when it comes to redeeming multiple seats together, long-haul across the alliance, without unnecessary garbage fees.
If you're solely talking quality and are specifically after SQ F, then native SQ miles are probably better.
AS is a mixed bag. There are some sweet spots in the program, and some areas of very poor availability. There's a lot of bang for your buck there if you have tons of flexibility, but converting to AS in hopes of a specific award on a specific date might leave you disappointed.