I have seen some literature on the hybrid hot water heaters. What would be the best for a replacement hot water heater. There is 4 of us in the house and nothing abnormal about our HW usage.
Where is the house located? I am not a fan of hybrid water heaters for my climate in Portland Or, but there are places they work. Do you ever run out of hot water? A pro really needs to take a look at the house. I have a tankless in my house but its usually not very cost effective to have installed PROPERLY with gas lines sized correctly and plumbing done as specified.
I think for tankless the Rinnai models are often the best bang for the buck as far as reliability, efficiency and price. There are less expensive models but don't expect them to work as well or last as long. There are more expensive higher efficiency models but don't expect the price to be in line with others.
What are you replacing and what is your climate like?
I am in NYC. Very high electric rates.
The US Department of Energy has some work sheets to help choose the most efficient way to heat water using your current energy prices.