I would have to say that if rock solid, dependable commuting is what you want, under ten miles, then a modern scooter would be both dependable and good mpg. Or the smallest cc jap bike you can buy. These are highly reliable, solid machines.
When I took my MSF course, the teacher talked about the ultimate reliable bike: no spokes to adjust, electronic ignition (never needs adjustment) disc brakes for city traffic, electric start for ease of use. My bike has none of these. I love it, but if I had to ride five days a week, no matter what... I'd probably get myself a Honda Rebel or some such.
The RE is a tinkerer's dream, but if you are looking for low maintenance, perhaps you should look elsewhere.
A Trabant, hey? Now there's a nightmare.