Jill and I have taken a plunge and bought a small (1100 ft2) house about a mile away in West Tisbury. I have a couple more posts tee'd up for House 5 on window insulation and on the electric mini-boiler I've installed, so stayed tuned (I've been really busy with the Zero Energy Homes Online Course, for one thing). I just blower door tested this new house on Sunday at about 3,100 CFM50, so there is more "opportunity" than House 5 offered :-) - that's about 0.6 CFM50/ft2 of shell, which is 3-1/2 times worse than House 5 was when we started on it. A huge chunk of that leakage is because they made a small attic in this one story home that is vented to the outdoors, and that's where they installed the furnace and ductwork (don't try this at home.)
http://www.energysmiths.com/resources/house.htm
New house below