I would love to c&p it here but the nest ate it!! I was posting it right when the site was changed over. I wrote such a long informative post and poof it was gone. Boy was I mad! Just another reason why I need to write some more blog posts on this stuff. I could have just replied with a link that way.
To sum it all up no you don't want a tankless electric water heater. They shouldn't even be manufactured. They use a lot more energy, have a high first cost, cost a lot to install, and sometimes require new lines to be run to your house.
Hybrid water heaters don't have a very high return on investment either. I did a quick calc for a previous nestie and it would take 14-15 years for the unit to pay for the increase in first and installation price. They make it very hard to replace the electric resistance coil inside to replace it (again needs to be done every 10 years or so) which normally a super simple DIY project but with hybrids you often have to hire out that job. A good general rule is that you should only even consider hybrids if they are going to be outside of your house like in a garage (very common in warmer climates). Otherwise your furnace will have to work harder to warm your house whether you have it in a finished or unfinished space. The heat pump on top is the exact opposite of a refrigerator or window air conditioner so it's cooling the air all around it. As the air cools the heat pump draws less and less heating out of the surrounding air and the electric coil has to kick on. Additionally, the max the heat pump can do is heat the water only 50% of the way. The electric coil has to do the rest. The electric coil is same size as a straight electric unit as well in case the heat pump is broken or isn't getting any heat out of the space so that part isn't any more efficient than a straight electric. Hybrids have fiberglass bodies so they have the same maintenance as I mentioned previously.
Personally I would stick with a 95% efficient metal bodies water heater. Or the fiberglass one if you have acidic water.
The desuperheater I mentioned before only works because we have a full geothermal air to water heat pump in our house. I was just explaining that that is why we undersized our hot water heater. In the summer months when the vertical bore system is trying get rid of waste heat in the ground it first runs through a heat exchanger that preheats our 50degF well water before going into the water heater. In the middle of summer it could get it up to 90degF so our water heater only has to heat it the rest of the way to 120degF.
The whole change over/post eating is completely absurd. They must be cutting corners on their tech team over there, because I have never seen anything so ass backwards and poorly done.
Thanks for retyping all that. I seriously appreciate it. Your answers always end up making me learn more about this house!