I've got the both old and new versions of the PX boots and have found the newer ones to be quite a bit smaller than the older 'Das Boot' version. I'm a wide-ish size 46 and the old Das Boot in a size 47 had quite a bit of room in the toe box, I could wear them with two pairs of socks if needed. However the new version in a 47 is a rather 'snug' fit, TBH they're a bit of a struggle to get on (they haven't got a pull loop at the ankle which doesn't help), but that said once on they don't move around as much as the older version and are still comfortable after a 4 or 5 hour ride. They don't rub the crank arms either which is nice bonus!