GW = ease of use.
CFW = boot this/boot that/cold boot my dick, convert cia's, install cia's, don't like cia, uninstall cia
sky3ds = locate header, buy header off ebay, get screwed because you thought you bought a private header but was sold to multiple people, buy your own card, have someone pull header and hope to god the guy pulling the header doesn't keep one for himself, get screwed again, finally got private header but have no luck inputting new header, finally input new header and come to find out sky3ds made new card to battle encyption, buy new sky3ds+.
Buy what you want or use what you want,