Not trying to pee in your cereal. I answered why I don't get excited about new parts. Cranks sized not only wrong, but not a Rod throw the same. Then you get to tell the customer why you are grinding his new crank.
Cams that don't match the cam card. See that a lot with OTS stuff.
Core shift.
Valves that look like they were ground with a right angle grinder, and the 45 is actually 42.
It goes on and on. It's just work.