I know two big men who rode aluminum frames and both had cracks after 30 or 40k miles. Fred owned a Fuji and it cracked at the junction of the sear tube and bottom bracket. I had a 5 year guarantee and was replaced. The second frame cracked in the same place after the guarantee expired. Fred weighted over 200 pounds.
I don't know the mileage of Travis' Cannondale's , but Cannondale replaced them under the lifetime guarantee after they had cracks..