probably 3 to 4 hours. Hard to say if the activation problems here are typical of every install as the easy installs often go unreported. If they are, then I wouldn't be surprised if it's 5 or 6 hours.
Most of the install time for my system was waiting around for 5 devices to download new code and program themselves. Since you have to do one at a time otherwise risking bricking the units. That was 2 hours just sitting and watching a screen. The actual time spent hooking up cables and setting up remotes was maybe an hour. If these units could some how come from the warehouse already up to date then that would save a lot of technician time keeping my couch warm.
My install just took one tech 4 hours. This included a new dish and running one new coax line through the attic to a new TV location. It was his first H/J install; he seemed to follow the printed directions he had and didn't have any problems.