Dolphin Compression

[ugoo]

Ok i was thinking of compressing my games with Dolphin to save a little space till i get a new portable hard drive after looking through the forums however and reading of some peoples games corrupting after compressing i want to be 100% sure that Dolphin's compression works properly and what size i should get after compressing a gamecube game, a normal wii game and a Dual layer wii game thanks