What are the major differences between regular and diet soda?

The primary difference is the removal of a natural sweetener , sugar, which has about 800 calories per cup. 1- 8oz. serving of a popular cola has around 100 calories. So this 1/8 of a cup of natural sugar is replaced with one of 3 artificial products. These have almost no calories. So the obvious health benefit of not drinking 1/8 cup of sugar must be weighted against various claims and counterclaims of these other products.