Yep, there is no such thing as bullet proof. The closest thing to that is stage II and they are not bullet proof either. Things breaks when you think that way.
There are allot of things to be factored in. It's not always power that breaks it. Something as stupid as a cheap oil filter can ruin your motor. Specially if your trying to push high viscosity oil through it. Something most people never think of when using them. Even though they been advised they still use the cheapest filter available. A big no no.
Finding a builder who knows what he's doing is important. Even more important is a educated end user.