My husband and I have used wedge pillows for back support when sitting up in bed for years.  It was time for a new set and I ordered these because I love memory foam and I wanted something bigger than what we have had in the past.  This has a very large width.  It is so well made that it appears to simply be part of the bed.  They are very comfortable.

Pros: Large and comfortable
Cons: May be too large for some  (however,there are other sizes that can be ordered).