I just flew the SQ A359 in C, and was floored by how spacious the aircraft felt. The ceiling height felt like 11' and with the 1-2-1 layout, the aisles were pretty wide. I caught myself looking across from my window seat to the other side of the cabin and thinking that it was wider than the A380, which I flew my outbound on (of course it isn't).
I won't get into commentary about the soft product, but the hard product on the 359 was outstanding. Compared to the UA 77W, not close, of course. If I were to think just about the airframe, however, the 359 has the Boeing beat. I think the lack of center luggage overheads adds to the feel.