Do you find shopping for a mattress like shopping for a car? I want to purchase a new queen mattress (and box spring, though I always wonder if I could just get the mattress and keep my original box spring) and I was wondering if you had any recommendations. I'm just looking for a good firm mattress. Probably spring/coil (not foam). Where do YOU shop that you don't feel like you're being fed a line by the sales people?