This is purely anecdotal. I am not much of a cyclist and certainly not fast. I showed up to a bike club ride when I moved to a new city with a borrowed SWB Vision; for all intents and purposes this was my first ride on the bike. The ride was just supposed to be 20 miles at 12-16 mph. Because of who showed up it wound up being 33 mi at an average 18 mph; I had no trouble keeping up, and I was barely sore.
The others' complaint was that they couldn't draft on me.