M&M's (LX) mileage chart is steeper than UA's for many awards (for instance: N. America to S Asia in F is 145K for UA, 180K for M&M). The one big advantage to M&M is they have access to SQ inventory the rest of *A does not, which might be useful for SE Asia travel.

I would actually dump the miles in US (in fact, they are my "*A place to dump miles", as I am similar to you: no real need to use *A except quite occasionally or for award travel, as my travel patterns are covered by other airlines). Award levels are better: North America-North Asia on Star Alliance (includes Japan and Hong Kong) is 90K in C, 120K in F, and can include a free stopover in Europe (which you can't do on UA, as they have maximum permitted miles rules) for an extra 10K in C, 5K in F (and sometimes US forgets to charge this).

In addition, US regularly runs 100% bonuses on purchased miles, meaning topping off an account for an award might only take a few hundred dollars, and regularly runs promotions that give cheap miles (like this months' Grand Slam).

The catch with US is that dealing with their customer service to get awards is painful (as many are fairly clueless on how to handle them). Once you get past that, though, I've heard quite good things about TG's BKK-CDG service in F (on leased 9W jets with F suites). I've also redeemed US miles for LX HKG-ZRH in F (as have others).

UA does have one-way awards (US does not) and some interesting partners (EK, QR). You might also try AC: I've heard good things about Aeroplan- similar flexibility in routing to US.