I have an S5 vwd and having come from a trek I'd say it feels stiff and less compliant but have got used to that. I have found the broad beam frame more susceptible to cross winds. Although once I put aero wheels on it the frame was least of my worries in a cross wind!
Biggest issue I had was mounting a saddle bag for spares on the aero seat tube but managed to jury rig something. Over all very happy with the bike. I do secretly lust after a Pinarello though...
Good luck!