From my understanding, US is as good if not slightly better than other airlines. It's relatively easy to check availability. Log into your US Dividend Miles account and there will be a link to 'Redeem Miles'. That will take you to a booking engine where can check availability.

One big advantage with US is the Premium coach awards. These are immediately upgradeable into FC using various methods. As a CP, I can upgrade any Premium coach award at time of booking based on my status alone. These awards 'cost' the same or slight more than Standard FC awards, but are not capacity controlled. A good deal for elites.