Ride report: I rode the first two-thirds of this ride yesterday. It was the fourth annual ride. Apparently the route has been very similar each year.
The ride started with about 40 riders of ALL different skill/endurance levels. The organizers encourage this, so they created several "bail-out" spots along the ride so that riders who don't plan on riding the whole thing can head back to the start/finish point. Many bailed at the halfway point, and I'd say there were 20 or so that continued past this. I talked to a rider who rode it last year, and he said there were 10 or so that finished the whole thing.
This ride is for camaraderie among cyclists much more than posting a good time. There are lots of opportunites to talk with other riders about cycling, and compare & talk about bikes. Early on there were three or four groups that separated based on pace. The ride got faster as more of the inexperienced people dropped out.