Originally Posted by
Al1943
It depends on how much stretch you ran the chain with, and on what the cassette cogs are made from, and your riding style and terrain. Assuming the chain was never stretched more than 1/16 inch/foot, and assuming the cogs are good steel. I would expect somewhere between 10,000 and 20,000 miles for the cassette when riding flat lands and rolling hills.
Your post is full of great advice. Also I would add a clean drive chain last longer than a dirty one. Dirt, grime, and road debries are chain, and cassette killers. IMHO.