There looks to be many more differences than just a aero frame. On the Cervelo, there was aero wheels, and an aero handle bar. That handle bar, while looking ugly, is the most aero bar on the road right now. I am sure with just the frame, the difference would be much less.
I own an aero frame with aero wheels, and I love the look of it, even if I built it on a budget. I also started racing, and have had some success in cat 5, but that's only cat 5. I'd like to think my frame helps me, but its mainly placebo.