Re: auto shift bikes
I test-rode an autoshift bicycle in the summer of 2009, found it gimmicky. It's a neat system for those who don't know/like the act of shifting gears properly.
The mechanism senses load and shifts the ratio up or down automatically for the rider.
If you're an experienced bicycle rider, you probably won't like the system (unless you are really sick of shifting), and I wouldn't motorize one.
You kinda defeat it's purpose that way.