Glad I found this website seems like a wealth of information

Our plumber installed a 75 gallon gas power vent Bradford White water heater in 2000 when we built a new home. In July of 2006 it started leaking, we were just shy of the warranty expiration so they replaced it and the same plumber installed that. Now the replacement that is not quite five years old is leaking again, but there is no warranty on it. First my husband thought it was from the top of the tank by the valve, so he replaced the valve and sealed it good, and now it is leaking from the bottom. We are assuming it can't be repaired and are faced with getting a third water heater in 11 years! So that brings me to my questions.

1. What should we check before throwing in the towel and buying a new water heater
2. Did we do something wrong. BW said we should have done yearly maintenance such as drain the tank and
check and replace the anode. According to them, if you have a water softener which we do, they go bad quicker.
3. A local plumbing supply and service store told me we should have an expansion tank, which no one including
BW ever mentioned before
4. What do we buy now, based on our luck with BW it kills me to spend money on another one of their units but
they seem to have a good reputation with the professionals
5. Are we just doomed because all the OEMs are now using lightweight cheaper steel.

Thanks any help or suggestions are appreciated