The shoe is certainly different than the 13's but not terribly so.  They are definitely more narrow (I had to order a 2E) and the external appearance would lead me to believe there is less gel than the 13's.  Less gel doesn't necessarily mean less support since materials are always evolving.  The sole now has some harder plastic, similar to Mizunos Wave Creations, that I actually like and can get you an additional 50-80 miles of wear.  If you are a 40-50 mile a week guy/girl it is beneficial having a durable shoe.  I will report back after 100 miles.