I have booked 4 trips with AAA. I use a Disney specialist and I would much rather let him deal with the headache of prices for me. The AAA discount is small, and I got a PIN for a better one, which he applied for me.
Some people don't like to use a TA, they like to do everything themselves. Not me. He watches special offers, and will call me if something better than what I have comes out.
Not all AAA agents are Disney specialists, but I think every office has at least one.