I might have missed it, but I didn't notice too much in answer to the actual question.
A few years back, I helped compile and put into a report the data on testing of several different solar panels set up in the las vegas area on Motorized tracking pedestals. It varied by manufacture, and also varied a surprising amount on supposedly cloudless mid summer days, but the average output was approximately 80 percent of rated output at peak, and the output hit 50 percent of the peak right around 2.5 hours on either side of the peak output moment. None of the panels was set up on non tracking mounts, so I'm not sure how the output of those varied through the course of the day.
The thing that surprised me the most at the time was just how far off the assorted contractors were in "rating" the anticipated average output of the systems they were trying to sell.
