Flights: To go direct, or through "deal" sites?

My last post was on hotels, and if you read that, you'd know that we have busted those bargain sites!
We're going to try again, and see if those sites really are good for something- except this time we're doing flights!
*For this trip, we'll be flying from Toronto Pearson Intl. (YYZ) to San Antonio ( SAT).
*Prices will be based on round trip (Wednesday June 10th-Thursday June 18th) for 1 adult.
*Prices are without taxes, and without booking fees and currency will be listed beside the price.
* The flight will be on American Airlines, and will be cheapest possible WITHOUT discounts!
* Number of stop-overs will be listed.
* **These prices are for round-trip, not one-way***

American Airlines- $340.80 USD- One stop-over both ways
(http://www.aa.com/)

Orbitz- $321 USD- One stop-over both ways
(http://www.orbitz.com/)

Expedia- $433 USD- One stop-over both ways
(http://www.expedia.com/)

Travel Hero- $440 USD- One stop-over both ways
(http://www.travelhero.com/)

Hotwire- $472.04 USD- One stop-over both ways
(http://www.hotwire.com/)

Travelocity- $433 USD- One stop-over both ways
(http://www.travelocity.com/)

What is up with this?!
We've busted those deal sites YET AGAIN!
The only deal was Orbitz.com and it was only a $19 savings!
You're probably going to end up spending that on baggage fees!
It's really up to you now,
Are you going to book with the company and choose your seats, or book with the deal sites and hope you're not stuck with a wing!

Happy Travels!