As for the PC board discussion, a high quality PC board made with thick traces, plated thru holes, and solder masked, made on a G10 or FR4 substrate, should last the whole life of the amp unless it gets cooked by too much heat. But point to point or turret board construction is of course much better from an amp tweaker's perspective, and allows for component replacement working from just one side of the board. They both have their advantages. I prefer turret board or point to point wiring in my own amps but for large scale production of an amp that will probably never be modified, good quality PC boards are the way to go.
The problem with PCB's seems to be that manufacturers are designing them cheaper and cheaper, closer to the edge of failure. Looking at a PCB from the 80's vs. what is being made today is a very different story.