Hmmm... Durability hasn't really factored into my reasons yet. I much prefer to use steel tanks, especially in cold water, because the weight I'd have to carry with AL would be a major PITA, while with steels I can get away with 10 pounds or less. Zero with doubles.
I own several AL tanks that date back to the 80's (my oldest steel is from '67). The only tank I've ever had fail hydro was a steel manufactured in '73, but I got that as a gift so there's no telling what it had been through. I honestly think that well maintained AL tanks (mine) will likely outlast me... and durability isn't really an issue.
Anyway, I like and recommend steel tanks for diving. They just feel better.
Rick