Starbucks and Jamba Juice use blendtecs...
I've never used a Vitamix so I can't say how they are in comparison but after researching both of them it seems you can't go wrong with either one. That said I own this blender and I love it.
Starbucks used Blendtec for a bit and ended up switching back to Vitamix last year.
Jamba Juice uses both depending on location.