I think I went up by like 10 gallons, nothing major. The only thing that made me think I made a mistake was the humming, but once that was fixed it’s been smooth sailing. Obviously it uses less power in the summer but hot water availability was not perceptibly impacted by the winter weather.

I actually have one and can echo that it will be fine. Replaced a gas water heater with a Rheem ProTerra model a little over a year ago, installed in our basement by Gen3 Electric. In everyday use (household of 5), the only times we might run short on hot water is if kids take baths back-to-back, and even then it doesn’t take terribly long to recover.

A side benefit is that it will cool and dehumidify your basement in the summer as long as there’s enough air flow in and out of the space where the unit is installed.

The only caveat is that Rheem had an issue with some units that caused it to make an ungodly loud hum when running the heat pump. The solution was a new fan which they provided and Gen3 installed for free, though it does require taking the top casing off the water heater so adequate space above it helps a lot - but I think by this point this problem has likely been resolved in more recent production runs.

Happy to answer any other questions you might have!

Interesting career change for Al Snow