I bought the primos one, can't remember whether it is the roar or the growl. Up until the day I used it in the woods, I had seen deer everyday. That day I saw none, and have seen a lot fewer since. Probably just a coincidence, but hey, it is an observation.
I've never heard this call in the woods either, but I'm in VA, which is a land full of hunters who seem to like killing young bucks. This leaves us in a situation where there are too many doe and the bucks don't get all that aggressive with each other, since there isn't much of a reason to. I'm glad I bought the call, for informational reasons only. It is now a toy that my kids play with at home. I also agree that it is a marketing thing, same with 99% of all the other stuff that's for sale.
I've seen a lot of bucks following doe and grunting their butts off. The true talker seems to be able to mimic these sounds, but with out the aggression in the mix as mentioned above, it too is relatively useless.
I am able to use the true talker as well as "the can" to bring in doe pretty often, so in my opinion having a buck follow the doe that I'm calling is really the only way for me to call with any success in my area.