Uhhh... Oh....
Not the boomerang Dawes.
http://www.bikeforums.net/bicycle-me...r-service.html

Did the kid ever get his CF upgrade?

A couple of MPH could certainly be within random variation. Or perhaps you just had a slow day, or didn't like the bike.

I did recently build up my first CF road bike, as well as first set of 16/20 spoke wheels. Since then I've been pounding on quite a few of my PRs. A couple of the short, faster ones are still elusive, although I expect they will eventually fall. The most progress was in a couple of the longer (7 to 10 mile) segments.

Of course, in my case, it could also be training.

However, I also have zero PRs with my bike that I mounted Tannus solid tires on.

Anyway, I'd probably look at:
#1: Tires
#2: Wheel design (spokes, aero, weight, etc).
#3: Are the hubs smooth? I'm not sure how important this is. But, even some of the old, non-labyrinth hubs can have very low friction.
#4: Body positioning?

I like high range, tight range gearing, but I'm not sure how important that is. Sometimes I'll find myself creeping along, and realize I forgot to shift from the small to large front ring. Other times I'll be spinning just fine at a good pace in the small ring.