I personally love every one of them (Okay I don't love Yojimbo but i do love Daigoro!) and I enjoy using them very much. That's whole reason I am not forbidding myself from using them. I don't know why but I just really liked the idea of controlling them instead of being harder hitting more mp costing magic like in older FFs.

Also, I liked their designs and the existence of new summons. Some people had problem with there not being a water aeon but since Sin is basically a gigantic aeon that mostly resides in water, I always thought having one on the team would be redundant.

I am serously thinking about long-time project of buffing up each aeon enough to take on their Dark counterpart.