Thanks all. If you do the mule ride you have to reserve a year in advance on the first day the reservations open each month for Phantom Ranch. Very difficult to secure. There is also a mule day ride that doesn't go to the bottom but is easier to reserve.
FYI my remarks on my GoPro camera not working right: the camera was fine but there was condensation inside the case that obscured the video after about 30 minutes of recording. That was my fault for using the underwater case instead of the normal vented one. I thought I was being clever, with maximum protection from Colorado rain. Not.