Many speedrunners and glitch hunters prefer V1.0 because certain minor bugs and oversights were patched in the V1.1 revision.
If you are browsing online libraries, prioritize sites with high community ratings to avoid malware. A legitimate LeafGreen V1.0 ROM should have a file size of exactly . If the file size differs significantly, it may be a corrupted dump or a different version entirely. Pokemon Leaf Green V1.0 Rom