Bunbun,
you're correct that older hikers tend to generally be more consistent than the younger hikers. In fact I hiked with a 65 year old who finished before i did and started on the same day, and then there was a fellow named Fixy who was around 60 or so who had already hiked the PCT. He started 2 weeks later than me, caught me, leap frogged a bit and ended up finishing 3 weeks before me. He hiked not fast, but all day.
But I think its more safe to say that older hikers spend more hours of day hiking than those of the younger "jackrabbits".
I neither fell into the categorie of people irordinately proud of their 20 mile days in the south, nor did I spend much time at all in towns. Neither did any of the jackrabiits i hiked with either. We didn't even really start hiking over 20 miles a day until virginia.
And 95 percent of the folks I hiked with finished this year, mostly slow and steady picking up speed as they progressed