We install Navien. They work great - for the most part.
Personally, I would not install a tankless, unless your hot water usage will be very high.
I know lots of guys here love tankless, and they can save $'s.
But 1 out of warranty repair will easily wipe out any savings.
We put one in recently, and it locked up when the owner changed his whole house water filter. Just a few tiny grains of debris locked up the flow sensor. Our fault? His fault? Who knows.
If I were building new, I would go with a power vent/40 or 50 gallon tanked water heater with a recirc pump if you want "instant hot water.
"Hey Lama, hey, how about a little something, you know, for the effort." And he says, "there won't be any money, but when you die, on your deathbed, you will receive total consciousness." So I got that goin' for me, which is nice. - Carl Spackler