Both campuses boast state of the art facilities. Main Campus enjoys the privilege of being huge with cricket and football fields. Once you get in one campus you can move to the other campus in the next semester by enrolling that campus's courses. From the teachers to the courses, everything is same between the two campuses. It's just that people who live near Main Campus, go there often instead of coming all the way to City Campus.
Conclusion, it depends upon the place where you live. Travelling is a headache when city conditions are unstable so choose the closest one. Start with the closest one and then try moving to other just to experience. It would be a great journey!
Best of luck! 
