Whilst I am still waiting for the OS X 10.11 El Capitan upgrade to complete, I offer a word of warning: as with other recent Apple system updates, progress bars are seriously non-linear.
Expect the progress to claim all sorts of time remaining, from 1 to 51 minutes, although it really doesn’t have a clue. Total time varies widely and could be as long as two hours.
I wish you fair winds and no freezes.
