You can learn a lot about your own quilitng by observing the quilts in the show.
At least I do!
What makes the show quilts awesome?
What flaws do you see in the ones shown?
How do my skills and the quilts I make match up to those in the show?
When I go to a show, I go with a personal objective as to what I want to learn ... eg. discover new border ideas, look at patterns/designs used in machine quilting that I might be able to use, etc.
Cons? Not sure how there can be any negatives ... unless you go with a sourpuss outlook!