I purchased the Simmons Beatyrest World Class Mattress three years ago.  Impressions have left the sleeping surface so uneven that I now suffer from back problems when I sleep on it.  I don't have these same problems when I sleep on other beds.

Simmons won't replace it because the pillow-top doesn't show impressions.  They disregard the fact that the impression is from a structural issue under the pillow top.

Horrible mattress!