So my design uses all-new components. The power supply can handle a lot more power than the original GBA. And I spent a lot of time improving the audio - so basically, the main selling point is the audio clarity. It is, truly, crystal clear. Check out the recordings:
github.com/MouseBiteLab...
A recreation of the original Game Boy Advance, with some modern upgrades including crystal clear audio - MouseBiteLabs/Game-Boy-Enhance