[Blackbirdws6]

I think you should be learning toward a standard but energy efficient water heater.

A tankless system does and can work but they require proper sizing to deliver enough consistent hot water at a given time. Some of this can be due to improper sizing. If you need a larger unit to supply what your home needs, you may need to also upgrade the electric as these units can draw heavy electric load to heat the water up at a given time. These units are more energy efficient than the standard capacity water heaters however the initial cost produces a return on investment well off into the future (think 10-20 years). These units also require a bit more maintenance as they are prone to needing a good flushing to remove any scale build-up.

Again, not bad technology at all but just weigh in all the options. For simplicity, I would go with the most efficient capacity water heater you can find, insulate those copper pipes in the crawl space and call it done.