Erik -
I totally agree. I speak from the hard experience where the contractor originally building my home ran out of positions in the SE panel and rather than put in breakers with two circuits per box position or add a secondary panel, they just put the last 4 rooms on the same circuit. Running the toaster and the garage door opener at the same time always popped the breaker.
When I redesigned the home, I put in a new main SE panel that was the max allowed by the local utility and then added several subpanels throughout the house. With well-marked and dedicated circuits available, it becomes very easy to isolate my gear when desirable.
If the stud walls are still open, it is trivial to run separate circuits for your power amp and your lower-power devices. I also got a deal on some cable so I ran 1/0 aluminum from the main panel to the subs, so there was minimal drop to each of the 60A panels. By running some #8 cable for the power amp back to the subpanel, that gives a fairly stiff source for the amp to draw from, and compared to the cost of the designer cables used between the wall socket and the devices, the extra in-wall cable cost was almost trivial.
#8 has twice the max allowable ampacity of the #12 that is almost universally used for residential outlet circuits, so when the amps ask for power, the in-wall wiring can provide it, potentially adding some punch to your music. You just have to be careful to get #8 copper, not aluminum to get the full benefit because aluminum is used for the larger wire sizes because it becomes much cheaper, but the conductivity is somewhat less. When you get up to sizes like the 1/0, those are almost always aluminum, and at that ampacity, the droop caused by the draw of your amp is minimal.