I hate the waiting for hot water, more than I hate the waste.
Heating up the pipes and afterwards when the water in the pipes cooling off.
I've seen info about under sink heaters and I accidentally burned my hands
while I was spending a night in my uncles guest house.
Instant hot water can surprise you..
I've been thinking about one for our bath room.. If I could find one that
only used 1200 watts (@120vac) when water was being used,
but not hold warm water 24/7..