Depends on who and what I suppose. I installed an update to the Sync stereo in my F150. Apparently it's an appliance version of Windows, go figure. Ford just put it on their website with instructions. Actually, now that I think on it it has a CD player - never once used it.
At work updates were constant off hours OT. The stuff you work on and what I did seems to have one similarity - whatever the thing is it isn't one monolithic gadget it's a collection of interworking systems each with their own idiosyncrasies. In many cases I had to collect it all ahead of time for lack of network access. I used to leave 'Doomsday kits' at my job sites and I guarantee many are right where I left them - all recovery media necessary and it was usually a mix of various sorts of formats