I came across a March, 2013 review of the Shakey's in Warner Robins, GA. The review is credited to Eaton Wright of the Macon Telegraph. I read other reviews by Eaton Wright, and believe the critic is older, as there are references to now-closed Shakey's in Georgia.
This quote from the review got my attention:
"..............diehards will tell you they barely notice their surroundings as soon as that unique smell of Shakey’s pizza greets them at the door."
The full review is here:http://www.macon.com/2013/03/29/2414785/choose-shakeys-for-nostalgic-family.html
Now this critic is experienced, so would know if the smell is coming from, say, spilled beer on the floor of a carpeted restaurant. Note that the two words THAT and SMELL are in the review. Warner-Robins reportedly still uses a deck oven. But the samples I get come from a store with a conveyor oven. I think there is more to it than the oven used.
I keep posting hoping that someone can place THAT SMELL(tm)*
*THAT SMELL is a trademark of DNA Dan.