Traversing Marlowe is a bit tedious but the road on to Henley is fair enough. Alas alack, its doesn't compare to the scenic option which is fabtastic on its day. However, Chiltern lanes are not a place you want to be early in the morning after a hard frost, believe me.
Its a funny thing but as an organiser I'm far more risk averse than I am as a rider. I'd much rather riders came home complaining about traffic than bruises. Let's face it, it's January, the days are short and cold, and it's about getting round safe and sound. If the weather is mild take the scenic route by all means otherwise please enjoy a fast passage to Pangbourne.
*end of speech*