Call the hotel directly and check which room they put you in. The hotel can tell you if you're put in a smoking room/king room, etc etc.
We've used priceline many times and 9 times out of 10 they put us in a smoking room and because DH always calls the hotel 1/2 hour after making the reservation, the hotel was able to change the room assignments around and give us non-smoking, double/queen beds.
We've never been treated any differently at any of the priceline hotels we've been to, including Hilton, Marriot, Grand Hyatt, Four Points Sheraton, Country Inn. They always treated us just like any other guest.