Here is the definitive guide to why the WE13 PS2 ISO is better, where to find it (safely), and how to make it shine on an emulator.
Perhaps the greatest reason for the ISO’s longevity is its limitless moddability
The "Better" tag often refers to patched versions of the ISO. Look for:
Why Winning Eleven 2013 (PES 2013) on PS2 Remains the Superior Soccer Simulation
: Since many high-quality versions were Japan-only releases, "better" ISOs often come pre-patched with English translations for menus and commentary.