The TCR that I used to race is, pretty obviously, the "fast" bike. But only because it is set up more aggressively and I can go lower. On a technical descent I'm probably faster on the slightly heavier custom steel bike with the triple, because it handles a bit better and I'm more disposed to go for it on the turns.

EDIT. @Barrettscv that Serotta looks as if it would fit me perfectly, should you ever get bored with it...