Unless you have a large family or entertain a lot it's not a good deal
Spend $1000+ to save $1-8 a month, Maintenance: heavy Expensive, parts Expensive repairs
(because of water deposits it needs to be flushed out once a year with chemicals...)
My tankless has been going strong for about 7 years. The hot water temperature is very stable and never runs out.
For about 9 months out of the year, my gas bill is about 1/3 what it was with a 30 gallon water heater.