Bloodshot,
My aluminum sprocket stripped between Valentine, Nebraska and Albuquerque, New Mexico. I'd adjusted the chain by the book in Valentine and lubed it. The last time I lubed it that day was in southern Colorado and the teeth looked good and the chain was adjusted right. But even if it was starting to look worn, there wouldn't have been a thing I could do about it then and there. By the time I hit Alburquerque the teeth were bumps. Good enough to cautiously make it to a bike dealer and eventually come up with a solution.
My advice stands. If you ride more than pushing distance from a bike shop... OK, if you ride more than a few hundred miles at a stretch and aren't always close to a stocking bike shop...then steel is better. It will let you down gently, degrade gracefully, rather than suffer the kind of catastrophic failure I saw.
It cost me $300 to get out of Alburquerque with a new chain and used OEM sprocket (shop labor, mostly).
-Don