Jan Heine has published the PBP equipment survey he conducted for his magazine, Bicycle Quarterly. See the study Here.
The conclusion he draws, as you’d expect, is that equipment choices don’t make a significant difference in whether someone finishes or not. Still, I’ve finished on a racing bike and a randonneur bike and was much more comfortable on the randonneur bike.
It’s fun to see where your choices fit in with other riders. I was in the majority of riders who chose steel bikes and leather saddles, but in the tiny minority who used 36-spoke wheels, 32mm tires, and full fenders. Interestingly, the common wisdom that it’s better not to bring family to PBP is actually true, according to Jan’s survey results.