Hi Jim--I hope the sausage came out okay. I have never made sausage but I use a lot of file' and learned how when I lived in south Louisiana. They most commonly use it to thicken gumbo, which is traditionally thickened either with okra as an ingredient or with file' gumbo powder. If you use it for gumbo, be sure to sprinkle it over the gumbo in the bowl, not the cooking pot. It does not reheat well in gumbos and soups and may get gummy or otherwise generally icky. As you know, it is not spicy but just a gentle seasoning which is supposed to encourage perspiration (that is, it makes you sweat--not too hard to do in south Louisiana!) There is no difference between brands as they all have the same one ingredient.
Hope you are still reading this question posting--this is such a good site and there are so many postings that the list moves along pretty fast!