If the question was does more miles make randonneuring easier or more fun? I doubt more miles beyond a certain distance makes a rider more fit. Some coaches say too many miles creates too much fatigue and holds a rider back. The motivations and interests are so diverse, I doubt there is a common theme other than there are way more brevets now than in the past and at least in my neck of the woods (NJ and PA) they are impeccably run. There are not a lot of 300-400K perms but one could do 2 x 200K? Or 200k + 100K. It seems the perms often leave from the same area (the perm owners area)