I have been demoing the Power and currently have the 155. I do notice some rubbing and the saddle is wider than what I am used to.
I will say that at times the saddle feels like there is nothing there. It's pretty cool. But that goes back and forth. I will put 40 miles on it tomorrow AM.
I have a Selle Italia SLR Superflow coming. That is a shape I really like, so I am looking forward to comparing them.