Brettstoner: Your logic is perfectly sound and I agree with you. Fortunately, while lacking specific automotive knowledge relevant to transmissions, I am an automotive engineer and know all about materials so I plan to inspect the parts when the tranny is in pieces at the shop and I can make my own risk assessment as to the condition of the parts they are putting back in. My car is only mildly modded and puts out maybe 200 lbs to the wheels so even without seeing anything I think the risk of hard part failure is low as long as I can control heat soak and torque management in the computer. But again, as you correctly pointed out, if there are any signs or symptoms of impending component failure I will change the parts, whether they help my car go faster or not. My last tranny blew the PCS right after being re-assembled so it had to be done twice. I don't want a repeat of that so your advice is well received.
Have to disagree about GM being efficient though. They apply a pretty liberal safety factor to everything. They also make design decisions that are heavily influenced by durability test requirements. That's why the choked the exhaust off by crushing the downpipe to almost nothing just so they could protect a [useless except for cat health] O2 sensor from some road debris. On top of that, there's all sorts of political red tape, design for manufacturing, design for ergonomics, design for the environment... everybody has their fingers in the decision making process and what you end up with isn't always the most efficient way of doing things from a performance perspective.
