I drive about 20K miles per year. Choosing a gas-electric hybrid like the Prius over a gas-only car was almost a no-brainer. However, deciding whether to pay the premium to go from a Prius to PiP is a little bit more tricky. If you don't mind paying the higher premium, you should just buy one because it is a better car than a Prius. If you're just looking to save money by using electricity, you should then crunch some numbers before buying one. For me, I only could charge the battery once a day, the saving would be very little even after the tax credit. PHEV Fuel Economy Calculator
I think importing oil is less of a concern in the future since the U.S. is producing more and more fossil fuel domestically. Reducing emissions is definitely a plus.
Better in most respects but maybe not so much if you have a flat tire somewhere remote while on a road trip.
