... This beeing said, how long does it take to put them on? ...
the fronts you can do very quickly - took me about 3 hrs because of installing new races into the hubs and re-packing bearings. the actual brake components might have taken 30 - 45 minutes to assemble and align.
the rears take longer because of removing the backing plates - i chose to grind off the rivets rather than torching them out based on guidance from Steve: the rivet holes need to be enlarged to 7/16 and if using a torch you run the risk of hardening the backing flange making drilling very tough. all in all, doing the rears took all day due to grinding, pounding, enlarging, repacking, races, and final assembly.
however, if i had to do it all over again, i'd do it the same way.