I have smoked Mixture 79 before...once.
The flavor and taste, to me anyway, was like Dr. Pepper poured over a urinal cake. There were some faint wisps of vanilla, but over-all it was not a pleasant smoke. And, you have to smoke it very slowly, or it will bite your tongue off, and turn into a sloppy, gooey mess in your pipe bowl.
I rate it as a typical cheap drug-store tobacco. There are much better tobaccos out there, for not much more money. Smoker Pride blends are a lot better, if you have to have a really cheap tobacco. They're not great either, but a lot better than Mixture #79 .