We just brought our '07 home to the mountains. We are replacing an Expedition with the Prius. I can't explain how huge the culture shock is moving from that tank to this great piece of engineering, but it's a good thing...
Made the exact same move from an Expedition to a Prius over 3 3/4 years ago. Have not regretted it for a single moment. Here are some fun numbers just to make you really appreciate your decision.... If you drive 18k miles/year (I do): Expedition at 13mpg (my average was 12city/14hwy) at $2.75/gallon for the first year you'll burn 1385 gallons of gasoline at a cost of $3800. Assume at least $1500 is your donation to the Middle East. Prius at 45mpg (being conservative since it's your first year): You burn only 400 gallons of gas at a cost of $1100. Bump your mileage up to 55mpg (that'll take a little time and practice) and you're at 327 gallons...a full 1000 gallons less than you would have used in the Expedition. 1000 gallons...just wrap your head around that for a minute. While you'll miss the living room like comfort of the Expedition's ride and that nice high seating position on the road, almost every other thing about the Prius is better, more satisfying and just plain fun.