I've used a bunch of Titegroup. But I don't really recommend it. It's not terrible. It's fine. And it actually gets clean around max load. I just don't see any need to shoot around max load with a powder that gets temperamental quickly above max load. I do not know how much hotter it is than regular powders, but I do know that beyond heat, there is something in it that is corrosive to polymers (or whatever the equivalent of "corrosive" is when talking about polymers). It killed a couple of FO rods of mine, and I initially attributed it to heat. But there is a photo somewhere here on these forums of the polymer cylinder of my powder drop, where later on I left Titegroup in accidentally for a few weeks while I was gone, and it
melted it, no heat involved. And instead of a stiff hard polymer cylinder, it was rubbery. So I don't know for sure if it killed my FO rods through heat or some other chemical process.
Some powders are dirtier than others because they're flat dirtier. Some are dirtier because of how we load them. There is a charge weight with everything low enough that you will not get a pressure seal fast enough after primer detonation, such that powder will blow out of the case into the chamber as it's igniting, and gunk up the gun.
As to a powder recommendation -- Bullseye is just amazing. It's old and dirty, but it's super consistent, super versatile, and produces tight groups. It's what I ultimately settled on for gamer loads. If I were loading 124gr for 1200+ with 9mm, I'd go with Power Pistol (which if memory serves is a variant of Bullseye, the same way BE-86 is).
But I still think the best 9mm SD loads are the 115gr Barnes XP/XPD. They are solid copper hollowpoints, so they expand more slowly than JHP, super consistently, aren't as significantly affected by barriers, and achieve the penetration of heavier 147gr JHP. But they are 115gr doing about 1100 feet/sec, which is a soft-shooting load. They're 130-ish PF. No need to load stout loads for SD practice if that's your SD load. You can use the same loads you use for the sports.
Rambling complete.