I had to replace my hot water system a while back and was interested in changing gas to electric, but plumbers I talked to all tried to disuade me from it. In the end I changed from the existing large storage tank system which was here when I moved in and which was massively innefficient for the usage required. I didn't want another system that was heating up a big tank of water all the time for no reason, and also was under time pressure with no working hot water, so switched to an instantaneous gas system which has cut gas use by a huge amount (perhaps 25% of what it was), so this at least a more efficient system for now but it's put off getting rid of gas for a good few years. The only other gas appliance I have is a heater which is rarely used, cooking is electric.
Yep, I have a new shiny gas instantaneous hot water and was originally irritated at myself as, unlike you, I didn't even consider an electric at the time of replacement (doh!)
But my gas has dropped drastically. My only Irritation with this now is the supply fees don't change here even if you use less.
another system that was heating up a big tank of water all the time for no reason
Shouldn't a larger system be, in at least some ways, more efficient? Since volume scales by r^3 and surface area by r^(2), a larger tank loses less of its heat to the environment.
I guess it's efficient in heating up a certain amount of water but the problem is that it was heating up far more water than I was ever using. The insulation of the tank keeps it warm to an extent, but the massive cut in gas usage suggests it was doing a lot of heating for nothing. The new one is efficient in the sense that it only heats what I need and has cut my gas usage.