I use a 40# trolling motor. Fine for docking or getting through bridges or out of a localized calm patch. I like the fact that even in light winds, I can sail faster, so I'm not tempted to overuse the motor

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I definitely like the fact that the motor is quiet.
If I felt I had the money, I would get one of the Torqeedos. They use a differnt battery technology, which gives more power for less weight. From what I read in reviews and other forums, they seem to be competitive to the smallest outboards, except perhaps for range.
To me, the fact that they are quiet, powerful enough for my pupose, and the promise of requiring much less maintenance than a regular outboard would make them a likely choice, if I ever get around to upgrading.