Here is why you need the USA version:

Menu music and superstar entrance themes are updated to high-quality audio files matching their 2014 counterparts.

Heavily modded textures demand more processing power. Lower the "Rendering Resolution" in the graphics settings to 1x or 2x PSP, and enable "Frameskipping" if your device is lagging. If you want to customize your setup further, let me know:

The search term "USA upd" refers to the specific region and patch version of the game. In the PSP scene, having the USA (NTSC-U) version is often preferred for better compatibility with English-speaking players and certain cheat databases (CWCheat).