For most players: buy the official Switch cartridge or eShop version for safety, online access, and to support developers. If you’re experienced with homebrew and understand legal risks, the modding community can offer interesting customizations—proceed cautiously, keep backups, and avoid online play with modified systems.
Some technical analyses indicate that the Deluxe version on Switch actually has slightly longer load times than the original Wii U version due to changes in texture formats and file organization. NSP vs. XCI: Key Differences new super mario bros u deluxe switch nsp better
While the Switch cartridge bus is fast, the internal NAND storage (where NSP files are installed) offers consistent and often superior read speeds. For most players: buy the official Switch cartridge
New Super Mario Bros. U Deluxe on Switch: Understanding the NSP Format and What “Better” Really Means NSP vs
If you must use NSPs, stick with (e.g., VENOM, SUXXORS) and avoid any repack claiming to be “better” without provided SHA-256 hash matching known good dumps.