Ok, our 40 gal gas water heater is failing. About 10 years old, which I
hear is ok.

But every time I talk to someone about their 40 gal water heater, they all
complain that they run out of hot water (comparable size homes and kids).

Bur our builder (and all builder's we spoke to when looking to build)
*insist* that 40 gallons is enough.

But we were always worried about running the wash or dishwasher before
showering, or two long showers would result in the 2nd losing water.
Complete with those water saving disks etc.

1. Is 80 gallons overkill? Perhaps I'm reacting viscerally.

2. Am I going to notice a large gas usage increase?

3. Are there rules in place limiting the water tank sizes?

4. Are there any particular brands to look for or stay away from?

I'm sorry for the barrage of questions.