During the Obama shortage, I ran out of Promo. I was using it for a lot of different handgun applications.
I ended up trying Titegroup. I found that Titegroup is also very versatile and worked for all of the stuff where I had been using Promo. It is also an "easy to ignite" powder that can be downloaded to mouse fart levels.
In general I like Promo a little better and went back to it for most (but not all) loads when it became available again.
A big plus with TG is that tends to be a lot easier to find during a shortage. Ball powders in general seem to be more available and less overpriced than flakes or the extruded stuff.
I may run out of Promo again before that current shortage ends. If so, I do have TG and know what it can do.
I have also toyed with the idea of trying
CBI (a bulk milsurp type of proposition). The price is good, but shipping and Haz are steeper than typical. A big order might not be a bad idea not only because of the shipping and Haz, but also to ensure you will never have to deal with "lot differences". Most of my Promo loads are "midrange" and well below max allowed pressure. For these, I am confident that CBI would work fine.