I had an HVAC guy at hockey who couldn't understand why I would not go tankless. He said I just lose heat with the tank. I said I didn't use enough water to justify the cost and of course he said tankless was even better for me. My argument as a low water user is say I use $200 a year and save 50% so now it cost me $100, a saving of only $100 a year, so it takes 35 years to pay the capital cost. A high volume user might save $250 so gets his payback much quicker. I assume their are numbers some where that compare a typical tank setup against a tankless. Unless of course, they would show that a tankless never really pays for itself over it's life expectancy.