review: after reading this thread I bought some schwalbe 1s for racing on which they feel good at, no worse than the GP 400s that I've used before. But seem to be much better for everything else, used them for the roubaix sportive on the weekend and got one puncture.
I've had this frame for 5 years, very pleased with it. No problems with robustness, including doing the Roubaix sportive a few years ago.