On the Grand Wall once there was a pair of east euro climbers behind us on the initial pitches and they were catching up to us even though we were climbing fast. We were simul-climbing through the merci me pitches and the euros were HAULING ASS and got backed up behind us as we got to the belay below the split pillar.
My partner and I, not accustomed to being passed, were like "you guys are fucking really really fast climbers - go ahead and pass us." So the euros start climbing up the split pillar and the leader doesn't really know how to place pro or jam, hangs on every piece, and in general is super slow. And we had to sit and wait for a long time for them.
After about 30 minutes, my partner really had to take a dump, and he insisted we bail. So it didn't really matter anyway.
So the mural of the story is east euros can't climb cracks. But Polish Bob can pretty well. And don't climb the Grand Wall if your partner didn't take a dump that morning at the Starbucks like everyone else.