Wew- that was a lot of advice, some good, some bad and a lot to sift through. The best advice I read was to keep your BMW until you find a scooter you can live with because after you live with one for awhile, you may find out you like the bike better. Scooters are about compromises, they do everything pretty well, where most motorcycles are focused at a particular task. You already own one of the best universal motorcycles ever made, so you already ride a bike that does everything pretty well. Now if shifting gears is tireing you out, then you need to quit riding altogether. But my guess is that you are riding over your head trying to keep up with the rest of the bikes. When I ride with my friends that race in either WERA or AMA and try to keep their pace I am pooped at the end of the day! A scooter is not going to help that, it didn't for me.
Here are some facts;
Where a scooter really shines is around town and in that domain the small ones excell; 50-150cc.
The 500cc T-max is known as the best handling scooter, yet a 250 Ninja will run away from it anywhere.
When riding the twisty's, the CVT transmission is always in the wrong gear.
The tires wear out far too quickly and replacment choices are limited and expensive.
All that plastic is expensive when dropped and comes in big pieces.
They are more maintanence intensive than most motorcycle.
With that said, I will always own a small scooter, they are just too convenient and useful. Although I put alot of miles on my Burgman 400, I wouldn't get rid of my motorcycle because of it. It is a nice addition to the motorcycles and complements them well. I spent a 3 day weekend this past fall riding the roads down around Mt. Airey, NC. and loved every minute of it, simply beautiful. I rode 800+ miles on the Burgman 400 that weekend and it handled everything I threw at it.