It will be interesting to see if the specialized turbo makes any splash in the market.

I made one myself (for 1/10th of the price). It is tons of fun and addictive. Unlike the poster above, I find it a problem averaging 25mph, as cars are constantly pulling out in front of me with a look of surprise that all the sudden I'm there. I can do 25 on my road bike (with a tail wind!) but usually cruise at 20 - don't seem to have nearly the issue of cars pulling out in front of me at that speed.