Well, that didn't take long for a comparison test to show up in this month's issue. Please note that it is not online yet (sorry). I'll summarize their results:
Prius: Ugly, slow in hybrid mode, ugly, really slow in BEV mode, roomy
Volt: Looks a bit like an Elantra, drives great, tight rear seating, quick, and worth the extra money
Winner (by a healthy margin): Volt
Prius: Ugly, slow in hybrid mode, ugly, really slow in BEV mode, roomy
Volt: Looks a bit like an Elantra, drives great, tight rear seating, quick, and worth the extra money
Winner (by a healthy margin): Volt