I have been going thru the same thing. I have a e350 extended van now and want to go to a transit connect. I drive my Ford Edge a lot for sales calls and service call because the e350 is just to big. But I put a lot of unwanted miles on it.

My final thought is going to a smaller van may involve more planning. if you work out of your house you may need to spend more time every morning planning ahead to make sure you have your supplies. So saving gas money could equal more time. Is the extra 30 mins every morning worth the $100-200 savings in gas.