We got one for our office. The brand is Titan, and I'm not sure which model it is, but it is a big one. It takes 2 30 amp 220 circuits to run. We don't use a lot of hot water there, but Dad did when he was laid up and showering there. The water is plenty hot and it will keep making it as long as you want.
It wasn't cheap, and it takes some serious electricity to run, but I'm happy.
If I were building a new home and it would be easy to get electricity and plumbing down there, I'd do it.