I'm in your same position.
In fact, I got quotes from both today.
Of course,
AAA was less expensive because they can discount the package with the dining option. BUT DU said they always look for discounts and codes and your cost would reflect any savings they could find, but there is no guarantee. AAA is about 10% cheaper according to my math.
I used AAA last year. Make no mistake, you aren't getting any expert or above and beyond service (at least not with my TA, may not be true of all).
I guess you need to decide if CRT is a very high priority. If it is, then I would use DU. But, then you may still want to sit down with the numbers and decide if getting the dining plan without the discount will still save you money.
Finally, you could always hope that a discount would come along that DU would find and apply.
Wow...that really cleared things up for you...
I hope some replies with DU experience are posted. I need to make a decision, too.