It's always good to have a backup hotel.
The best bet would be to check to see, (When the con rate opens up) if the Sheraton's con rate is comparable to the full booking price at the Stillwell. If I recall correctly, the Sheraton was one of the least expensive hotels at the con rate. It's also one of the fastest hotels to sell out, so it pays to keep checking the official AX website as to when they will open up the con rate.
The Figueroa was actually one of the more expensive hotels at the AX con rate. (Yeah, I don't how they stay in business either.) Uno must be relying on the huge busloads of European tourists to keep him afloat. He's expressed that besides disliking females, he doesn't really like Americans either, so Americans aren't necessarily his biggest clientele.
Anyway, best wishes & I hope that you get a good & close hotel!