Removed old tank and installed new tankless unit in an afternoon. Came back the next day to adjust some of the plumbing for a cleaner install, did not ask for payment until we were completely happy with the installation. Was careful removing the old tank even though the area was cramped and did not cause any damage to the house. The heater has been working fine so far.
Left the work area dirty but I cannot complain because their price was much better than some of the big names in HVAC.