bro 25gb is a blu ray raw......absolutely loseless. someone ripped it straight off a BD.........you should probably look for things titled BDRips instead. the difference is rips are encoded which in alot of cases is actually better quality as the filters fix some frame errors. the only reason people even upload BD raws is so others can rencode them
People seem to get stupid ideas in their heads that 25gbs must be super high quality. it isn't. most people avoid oversized files because they are generally a sign that the encoder had no idea what hes doing.
(I dump and encode every single BD i buy to play via xbmc and/or plex.)