Hmm. I thought, as I'd cycled 100 miles "with ease" once, that one of these audax things would be a walk in the park. I'd read the blurb; friendly mob, non-competitive, etc. But I nearly died. I hadn't done the maths and even the minimum time was pretty racey for me given my Hobbit-like riding patterns (eating-wise, not hairy feet or a golden ring - two breakfast stops, elevenses, long lunch break, high tea, and regular fag breaks to savour the view).
Admittedly, that was in my POB days when I rode a £199 hybrid and cycling wear consisted of taking off a jumper under my Barbour jacket.