For users running custom firmware (like Atmosphere) on their Switch or emulators on PC (such as Ryujinx or Yuzu), game updates are typically distributed as files (Nintendo Submission Package). These are essentially update files that you can install manually.
The "better" update NSP is the one that includes all 6 waves of the Booster Course Pass (48 additional tracks). A base NSP without the 3.0.1 update only gives you half the game. Having the full 96-track collection is the definitive "better" experience.
New logic prevents players from acquiring "strong" items (like Bullet Bill or Blue Shells) if they intentionally stop, drive in reverse, or repeatedly farm the same item box location. NSP vs. XCI Differences