Well, you've got to figure this business of his is just a side-line, not a main source of income, so that may explain the lack of rapid responses.
I have seen the innards of a regular Gold and a Gold upgraded to Maestro by MAR side-by-side. I wish I had a digicam so you could see the number of components that were indeed different. All the major cylindrical doo-dads (caps?) were changed, lots of the little resistors, the power supply torroid, the internal wiring, and numerous other little devices on the main board. I have no idea about the actual cost of the upgraded parts, but to the untrained eye, it did appear that *most* of the biggest and presumably most important doo-dads were replaced. I also got a bag full of *some* of the old components.
markl