Vanilla SoulSilver locked several Johto Pokémon behind the post-game (like Houndour and Sneasel). The ebb387e7 patch utilizes the "National Dex early" feature, allowing you to catch a wider variety of Dark, Steel, and Dragon types before the Elite Four. More options mean better team synergy and replayability.
: The original text speed, even on "Fast," is relatively slow. Advanced codes can make text appear instantly, significantly cutting down the time spent in dialogue during a 36+ hour main story . soul silver ebb387e7 better