Jeff -
You may have just gotten 'lucky' with those two.
I OTOH have NOT had good luck w/Chevy trucks. I'll spare the details but I promise the last one I had was FALLING APART on the road. Obviously millions of people love Chevy and get good service. (Let's NOT hijack this thread)
Wait...I'm counting, this is at least my 4th 300, plus multiple 7s, 338,and I worked w/a friends 375 HH. I experienced NOT ONE problem related to the belt.
I have a friend who HAD a Rem 700 BDL 30-06 that had a problem from the factory. Wound up being a BURR in the chamber. Simple solution..no other problem.
STUFF HAPPENS because HUMANS manufacture.
Jerry