Asia version is the same except the manual usually has a english/chinese sheet with the controls. Also I hear the quality of the discs they print the games on are a little worse/cheaper. I think that's probably true because the discs feel a bit lighter than Jpn ones. Still I've never had a problem with the Asia versions.
There are a very small few (under 10 maybe) games that are actually in Chinese, but sites like Playasia will say in big bolded words if they are.