I came from a running back ground, and had to stop running because of knee issues. Aero bars, wheels, and aero bike design will make a difference. Once you are dialed in you should have no power lose, if anything you should gain power with a proper fit. Aero bars, aero wheels, and aero bike design make a difference, and don't dismiss the mental advantage. Whenever I get on my Zipp2001 I feel that I have to go out and hammer out a ride, I don't want to let the bike down. Sounds crazy but knowing you have a rocket for a bike makes you push that little extra in a race.