Priceline guarantees a non smoking room and they've always been good to their word.
At least the hotels I've stayed at are relatively new and all the room are the same.
My only "bad" experience was at the Marriott in the Balitmore Inner Harbor. We wanted two doubles because my teenage daughter was with us. We got a kind sized bed, so I slept on a roll away. Also, the room was as far from the elevators as you could get, and that was far. But there was a large group of high school volley ball players staying at the hotel.