I would like to buy a queen size set.  Now I focus on two kinds. One is Paces Ferry Ultra Firm from Stearns & Foster which is sold $1899 by Havertys, the other is Stearns and Foster Deacon Ridge Luxury Ultra Firm Mattress which is sold $1619 by Sleepys. I tried 2 mattresses and felt similar comfortable. What is the difference between them? Should I choose the cheaper one? Thanks.

I don't know much about either of those mattresses but they probably have poly foam on top and it will start sagging in a year or so.  If I were you then, I would buy the cheapest of the two because you will probably be buying another in a few years.  I think you should spend some time reading this forum and seeing what others have found out.  Most of the folks on this forum have tried one or more of the "S" brand mattresses and are looking for something better this time around.  My suggestion is that you do too and maybe look for threads on latex or possibly memory foam.  My suggestion is latex.

Sleepys .... 700 location?!     Geez that's a lot.

I don't think Sleep Train has nearly that many here on the West Coast.  But hey, it's the West Coast ... sparse compared to East Coast.

Is $1619 the price you bargained down to? Sleepy's is called Sleep Country here and the price on the sticker is not the price you should pay. In my one and only transaction with them a few months ago (never again!) I got my bed for $1050 after a mere 20 minutes of dickering, when the sticker price was $2500. They inflate the prices,not expecting anyone to pay sticker price.

Read the helpful information on this site about buying a mattress.  Mattress salespeople might be lower on the food chain that used car dealers.  DON'T be in a hurry to say yes.  The longer you hold out and shop around, the better deal you can get.