I agree that "payback" would take a while for a Prius. I got one a year ago because I thought they are cool technologically. I haven't been disappointed from that perspective. My favorite feature of the car is the smart key system, which really has nothing to do with hybrid technology, but is very cool. I never have to take the key from my pocket to either unlock the doors or to start he car. The car knows when the key is nearby. I like the touchscreen controls for the stereo and climate control also. I do like getting 49 mpg vs. the 24 in my Passat. It is roomier than other high mpg cars-- as big inside as he Passat. I was surprised at the pep it has. Not like my turbo Passat, but enough for this 48 year old guy. It isn't for everyone, but I do really like it, despite the ridicule from my conservative colleagues-- I am a conservative too. I just like gadgets.
We like ours too, for many of the same reasons. On a recent trip to Florida from Delaware, even driving at 85 - 90mph, we could never get the mpg to drop below 41, and the "Nav Lady" is cool.
The ultimate geek car ...
My husband likes gadgets also, and he loves his Prius. We got ours 5 years ago, and we haven't been disappointed. We're trying to decide when to get our next one.