IME, revolvers with cast bullets are impressively smoky, no matter what powder. Under a jacketed bullet, no problem.
Out of an autoloader, my 9mm Unique cast loads are so clean I can rapid fire them indoors and most people wouldn't notice I'm shooting cast.
Cleanliness: I used to have some impressive white crud covering 1" of the business end of my 45, after a box of factory ammo. I reload 45 exclusively with Unique, and I've never had anything like that. After a hundred rounds, I can put my gun away without even wiping it off, and you'd hardly notice it had been shot. Internals pretty clean, too. I've tried 5 different powders, and all are equally clean. I think dirty ammo is often caused by loading a cartridge too light for that powder.