In terms of aesthtics its a matter of proportion and shape. Mila Jolavich and Gwen Steffani for example are very svelte women whose smaller breasts work with their shape. Kristina Hendrix on the other hand is a very voluptous and curvy lady who happens to be very naturally busty, also very pretty in her way. Same could be said of Nikki Minaj who as ample assets so to speak.

I am not personally not a fan of over done silicon, especially when its obvious and they look like basketballs.

In many cases smaller breasts are more sensitive to touch, and I know a lot of "bigger" women are not comfortable having theirs given attention (just from some conversations I have had in the past) but that too is really an individual thing.