So i have some games some are .iso, a few are .cso. When making ISO's on UMDGen 4.0 i notice it asks if i want to save as Uncompressed (iso) or Compressed (cso). I would naturally believe that .cso would be the way to go because it would compress the file to a nicer (i.e. Memory Stick friendly) size. But then i notice most games are ripped to .iso format...so that has me wondering. Is there a reason why larger iso files are more popular than compressed cso's? Do cso's not run as well or harder to load or something? What's the pros and cons of both formats?
CSO works exactly the same as ISO, the reason lots of people want an ISO is so they can edit it without decompressing it. In the odd case CSO can mess up when ISO doesn't, but not usually and it's never happened to me.
Also, sometimes multiplayer or something else will be taken out to decrease memory space that it uses.