Dear Janice: You're right, the U.S. is way behind the rest of the world in this respect. The Bosch Aqua-Star featured on Bobs' show has about 60% market share in the gas segment world-wide. I have sold Aqua-Stars exlusively for nine years. Med to high flow depends on where you live and the temp water you are feeding it with. For most households, the AQ-125B is adequate, if a high volume of hot water is needed or your cold water is very cold, then the AQ-170 will take care of it. All I do is show folk how to heat water. I have electric units from $265-$495 & gas units from $441-$1320. Please call Brian 800 851 9891. Happy Heating & Happy New Year.