Race specific is simply what you race, no?

My newest frame has a gigantic headtube, 170cm for a 56. It's perfect. I can slam my stem and still actually pedal.

Longer wheelbase too, so my shoe doesn't hit my front wheel when trackstanding. Two big pluses!

Add the BSA bb, and I'm happy!

I went from an aero frame to a lightweight frame (over a lb less for the frame). Can't tell a lick of difference. I'd like something aero and light, I guess, but again, no discernible difference.