Originally Posted by DGlenday

I ride:
- Short-fast rides (e.g. 26 miles @ 21mph), as well as
- Very long distances (about 8 centuries at between 17 and 19mph this year, regularly ride 130 miles / 200 km brevets at 17mph, did 150 miles at 17.5 mph last month, and longest single ride this year = 230 miles)
... All on a CAAD - at age 55.

So I'd suggest that although a CAAD is best suited to the first kind of ride I listed, it's pretty good at longer distances too.