DH and I, DFIL, and my parents all have tankless HWH and we all love them, my parents just had to replace theirs, after 20+ years and never once thought of putting in a regular HWH. I grew up with a wood burning hot water heater, it was a small stove that was hooked up to a holding tank, we started the stove every afternoon, summers included, and we would burn it a few hours and we would have hot water for a overnight.