i have a 2 year old pillowtop kingsize mattress and it developed "caverns" where my husband and I were sleeping. My caverns were giving me a backache so i decided to give this a try. i noticed an improvement the first morning-no more backache. i normally sleep on a neck pillow and these bonus pillows" are very comfortable. go ahead and order this if you are "giving it thought"-you'll be glad you did.