I have seen both versions of Ghajini. Aamir is a great actor. Surya is upcoming hero when commpared to Aamir. So i am not comparing the hero status but When saying particularly about Ghajini movie.
IN Hindi: 1) Aamir JI's hard work(Almost one year he practiced in Gym). 1) Song pictured is good when compared to tamil. 2) of course AR Rahman is good in music 3) Climax is better when comparing to tamil.
In Tamil: 1) Surya's acting as Short term memory loss Role is very natural when comparing Aamir Role. 2) Also Sanjay Ramaswamy role is good. Both are good. 3) Song and pictured are good but Hindi leads one step more. 4) Harris jeyaraj is assistant of AR Rahman four to five years ago. 5) Climax is messed up when comparing to hindi and it looks lengthy when compared to hindi.
Rating:
Hindi(Out of 10) ----- Song: 9.5 Story: 8.5 Aamir's Hard work: 9 Aamir ALL Movies: 9 Aamir GHAJINI: 8
Tamil(Out of 10) ----- Song 9 Story 8(Because of climax when compared to hindi) Surya's Hard work: 9(As he is young and good body shape when compared to Aamir) Surya - ALL Movies: 6 Surya GHAJINI: 9
Because of Surya's acting looks very nature when compared to Aamir espescially in the 1st half of the movie.