I agree with VCG. It's depending on how you see it.
People who love big maps would possibly dislike the fact that the map of IV will be smaller, but that is compensated for with a lot more interiors then SA ever had.
People who hated all the socializing stuff like dancing, dating, changing clothes etc would like the fact that in IV the character will focus more on climbing the crime ladder rather then go to a club etc.
And people who hated the detail in the cars for SA would like the fact that in IV there will be CAR BRANDS (yeyah!) and other details for the cars and bikes.