Looking at purchasing a 2012 Prius Five Series or a Prius V Five Series. Both my parents have Prius, so I know how much they like the for the mpg. I think I prefer the V Prius, but don't like that fact that it may get less mpg than the regular Prius and I am going to buy a Hybrid want to make sure I get the best mpg. Negatives for me are getting used to driving a Hybrid, since I have driven European cars for years. Positive is the excellent mpg and since I drive about 24,000 miles a year, that would be a hefty cost savings on gas. Also, test drove a 2012 Passat TDI SEL today that was just off the truck and averaged 44 MPG on a long test drive of city and freeway driving. More fun to drive than the Prius, but not confident on how reliable it will be.
Good luck on the choice. I assume you have test driven the prius for good amount of time? If not, rent for a week.