We bought the mattress for our stick house online at
Brooklyn Bedding (which is in Phoenix, right?) and are very pleased with both quality and delivery. Quickly delivered in a box that was actually quite easy to handle (but stand back when you release the straps that keep it compressed!).
We previously bought a Serta thru Sam's Club but were never quite satisfied with it. Sam's has samples in the store to try out and they did ok with sale & delivery, but it just wasn't as comfortable as our previous high quality mattress. We gave it to our daughter (she loves it) and bought the new one online from Brooklyn Bedding (after some research, of course).