This was hands down the most fun I've ever had in Austin! I've done the Austin segway tours before and I've gotta say, the E-Bikes beat out the segways hands down. My Fiancé and I had another couple with us and tour guides did a bang up job!
Rather than take the well beaten path along Town Lake where there's a lot of foot traffic, we rode along the Colorado river bike path toward the East. It's beautifully paved and the nature looked untouched. They did well to make sure we were well immersed in the surroundings.
The best part about the E-Bikes is that you can select the amount of 'help' you receive from the electrical assistance system. So if you're really fit and cycle all the time, you'll be well challenged on the path. At the same time, if you haven't been on a bike since you were in elementary school, you can crank that baby up and fly with pretty minimal effort.
All over, if you've got a few hours to kill before 6th opens up, or you're looking for something off the beaten path, I super recommend these guys!