I too watch "the boys" on TV call in long beards time after time only to have them wamp up on the deks. It's cool to watch and I to believe it does happen given the right situation. In a turkeys world it's all about pecking order. If you are hunting an area that has a dominate bird in the area, I feel during the breeding season he would be apt to march in and try to take the hens away from that strutting tom, but a suborbinate bird(could be a jake) may not be so eager to come in.
I use a jake dek most of the time and from time to time I'll have the bird I'm working stand toe to toe with the jake, other times they pay very little attention to it or my other deks.
My $.02 is like most things in the turkey woods, things work at any given time ,then tommorrow, "no go".
But, it does not hurt to have one in your bag of tricks