Sent a plumber & apprentice. My general contractor (who actually recommended the company) said that the plumber was dumb & slow (which I learned to agree with) and the the apprentice was better. The plumber made an number of errors (putting clean outs for one apartment in another instead of the basement, putting drain pipes farther from the wall than needed so they protruded into the room), complained about having to move the HW tank (it was heavy) and not wanting to remove a cast iron drain.