This is a hard one to write because we ended up not getting a bed here. But I can rate everything else.
They had a pre-Labor Day sale going. We were actually heading to check out Sleep Number, but stopped here on the way. Joshua was very nice, very friendly, and pretty low-pressure. Let us lay on different beds for several minutes each (it's usually best to give it 10 minutes before you judge), all the while telling us about the bed and comparing to others in the store. In the end he did his best to dig out every special he could offer us and we put down a deposit (refundable).
The rest of our bed shopping (e.g. Sleep Number) isn't really relevant here. After getting my hands on Consumer Reports I discovered that the top memory foam bed was sold at Costco, of which we are members. After doing a bit of digging on that we opted for the Costco offering. To their credit, Mattress Firm quickly and courteously refunded the deposit over the phone. We didn't even have to go back in.
So really the entire experience with these guys was positive. I would come back here again if the Costco mattress doesn't work out.