I always bought this collection and I was not disappointed with this mattress and box spring.  It has inner springs with a small layer of memory foam woven on top.  I wanted a good, affordable mattress, without all the bells and whistles.  I went for the low-profile box spring to keep the bed a bit lower than it had been with my old mattress set.  This new mattress is a bit deeper than my old collection, so the low profile box worked well.  I've had it for 4 days and find it very comfortable.  The only unknown is how long it lasts, especially b/c you cannot turn this mattress over.  I intend to rotate it, and also to sleep on different sides over the years to wear the mattress as evenly as possible.