Bike fit / correct riding position

What i don't understand though, is replacing your specifically built commuter Amey with a frame that has a repuation for being very thin walled, and denting quite easily, why not just lighten up the winter bike a bit?

Exactly, especially now that he got the fit sorted, he can put this toward the commuter with a longer stem, lighter wheelset and decent tyres.

Hell, my custom bike will be just like his commuter, except for the Di2 and hydraulic flaff.