I have a 50 gallon water heater that has never run out of hot water for my family of 6 so far. I just recently installed it, and it wasn't difficult to do at all, so the cost was just the water heater, hose, and some parts to install the thermal expansion tank (didn't have one yet). 12 year warranty. I was really set on tankless until I weighed costs and benefits, and I'm totally happy with the tank.

And should there be an interruption to the water supply to your house, you would have all that clean water in the tank to use.