American Pioneer Powder used to be called Clean Shot Powder. They got into a legal battle with Pyrodex when they introduced pellets or something as I remember. They then as many companies do when in legal troubles, re-organize and change their name.
Pioneer Powder I believe is a sugar based powder. And yes it burns cleaner then Pyrodex. You still have to clean the rifle. From what some have told me if you shoot Pioneer Powder be very careful of moisture, ie: rain and snow days, fog and damp conditions. It seems to draw moisture. All powders do, but some more so then others.
I have some clean shot powder here at the house and it shoots fine. When I run out, I have no intention of getting anymore. It was on sale and I bought it. It shoots fine. I have not hunted with it, but I am sure it would work just fine. This is not something I would use in a flinter, but for a side lock or in line it will be fine.
It is just a hair less powderful then Pyrodex. In fact measure it the same as you would Pyrodex, it is that close. Another good powder out there for those that hate to clean their rifles is Triple Se7en. It cleans up with just water and is 15% stronger then Pyrodex in loose form....
By the way, I use Goex Black Powder. Cleaning these rifles is all part of the sport.....