It is worth for everyone - I mean everyone - to study Thierry's GPS track on Route Gadget at
http://www.vmeyer.net/gadget/cgi-bin/reitti.cgi
You see him not only consistently picking the best routes but only one time when he has to stop at control to pick a route - good on the ourse setter picking that challenging leg but more importantly the tail of his icon keeps a consistent length meaning he is moving a consistent speed on the level and going up hill. His GPS track takes a funny deviation late in the race but I suspect that is just the satellites having trouble keeping up.