Suggest that you pick up 3 or 4 good loading manuals, watch the posts on several forums and pick a powder that catches your eye. Compare 'the one' with your books and evaluate it on paper. Maybe check two of three before you buy. Then take the plunge and get one can of 'it'. Try 'it' for a couple of hundred pistol rounds or 25 to 30 rifle rounds, then determine if you want to try another powder.
Every one has a favored powder, or two, and loads that work for them. Just because one person raves about one powder, doesn't make it good or bad, look for a concensus of several people and then, for safety, load within the brackets of safety in your book/s.
My 9MM load is 4grains of 231 under a 122grain lead coned flat base with a standard CCI Sp primer for 1032fps out of a SIG. It works for me.
All ways error on the side of safety,