Thanks everyone for the advice. I searched here and on the Yahoo list and this question hadn't been addressed that I could find. It will be nice to have this thread here for some other noob to search for in the future.
Yes, Billy, Tohatsu also makes Nissans and most of the small Mercurys. The only difference is the decal on the cowl. They're even making some of the not-so-small Mercs now, I see that the new "Mercury" 30 is actually a Tohatsu product.
I'd be interested in a Tohatsu 2-stroke if I could buy one new. The 2hp, short-shaft Honda weighs 27 lbs, not much worse than a 2-stroke. Maybe not as "polished" a product as some might expect from Honda, air-cooled, single cylinder so a little bit noisy and vibe-y, no frills, but that makes maintenance easy. No water pump to service, and for those in salt, no flushing to worry about. They hold their value well too if you ever feel the need to sell it. Hunting around for used ones made me realize you do just about as well to buy new and you don't inherit anyone else's problems.
Short-shaft is sure easier to carry, store, move around etc. I'm glad to hear they work well enough. I suspect if you ony had one motor and sometimes had to run in a pretty good chop that a long shaft would be better. But if you were in that situation, you'd probably want more motor.
If one was in a situation where one really had to motor a lot, against wind and/or tide, something more powerful would probably be in order, Suzuki 2.5, or Tohatsu/Nissan/Mercury 3.5. Those are the lightest weight motors in each of those power ranges. "Big" sailboat guys use a rule-of-thumb of 2hp per 1000lbs displacement for power, it's easy enough to figure out your weight of boat, crew and gear and come up with a figure if you were in a "power critical" situation. Also though, I suspect that the U20 outboard bracket would be a limiting factor to adding too much power. Like most of us, I'm looking for something to get me off the ramp that doesn't weigh a ton and is not a lot of trouble.
Torqeedo would be great, but the prices really need to come down. It's also hard to refill that battery from a jug!
For those of you looking for motor bags, you might want to check these guys out -
http://www.allinflatables.com/shopping/covers/cases.htmlI've ordered one but haven't received it yet. I can post a review when I get it if anyone's interested.