im not sure what the update does but it seems kinda large to just tweak stuff
well i do know that the 0221 client came out (or something like that number) so if you don't have that number, do update. even if you have like 1025 of 0117. Update frequently.
*sings to wedding theme* heeere comeees the gunssssss~
Edit: but seriously, its the gunner sprites, scripts, npcs, ect. Confermed in my test server.