Bruce tells me he can ride-out-of-the-saddle on his older monocoque Birdy - although its older Sport-stem has a angle slightly more than the 21° of the mk4.
I'm also hoping I can centre the saddle on the rails. Currently it's too far rearwards and, with our damn third-world-status potholed UK roads, the saddle frequently tips up - even with the nuts torqued well over spec.