Alto is much better than Mehran, obviously there are different classes of Mehran, Alto and Cultus. If you drive BMW or Mercedes then you will say Civic and Altis is a crap. So its totally depend on your budget, if you have a budget then go for Cultus, if you are not a tall guy then Cuore is a good car. By the way Alto VXR is not a bad upgrade from Mehran, you will feel the difference.
Regards,