My hot water demands are not extravagant. We have 4 people in the house and 2 baths but one only has a shower. 3 people will shower in the morning but not at the same time. I shower at night. The shower heads are High Sierra 1.5 GPM High Efficiency Low Flow Shower Head (highly recommended by the way). Wifey said that the new shower heads were stronger and better than the 2.5 gal heads I replaced. The Gaggenau dishwasher will run at night. Then there's the standard Maytag washer, 4 loads per week. My view is colored by the crappy coil in the oil boiler we currently are living with. It can't feed one shower so I will catch all kinds of hell if we upgraded and run out of DHW.