My MoOde Sound Tweaks

[Edward]

Not sure if GPIO and USB socket are different. Both require 5.2V maximum or so, give more – get a brick.

GPIO has better electrical contacts which is critically important for current peaks, that for sure.

Info from Raspberry Pi

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The 5V GPIO pins on a Raspberry Pi are connected to the 5V rail. Typically they provide the remaining power from the Raspberry Pi (that isn’t being used to run the board itself). So you can hook up the GPIO 5V pins to a 5V  source and feed energy directly to the board.


Connect a 5V source to Pin #2 (5V).
Connect the ground of that source to Pin #6 (GND).
Please be aware that there is no regulation or fuse protection on the GPIO to protect from over-voltage or current spikes.

If an incorrect voltage is applied, or a current spike occurs on the line, you can permanently damage your Raspberry Pi.

https://www.raspberrypi.org/magpi/power-supply/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Of course, to do this you will need a very good "Regulated" power supply. But then that's the whole point, feed the RPi very good Linear Regulated power. I've used the Jameco and other regulated power supplies without a problem. Others have as well without problems but if your home environment is prone to spikes and surges its best to fix that problem first.

I just don't see the point of feeding good power to a switching regulator.