Dude, get the 500! If you don't you'll always look at your GT and think of that 500 you had your eye on. You don't want that. You can get almost any mileage you want ( up to 24mpg or so) depending on how you drive it. I get about 13 in town but I hammer it every chance I get. Just 2 days ago I took the long way home and decided to cruise it. I reset the MPG calculator for the trip and got 21mpg. That included a few thumps too. So just get the 500 and have fun when you want to but also save the earth/your wallet when you want to.
DaFreak
DaFreak