Speaking strictly of handgun ammunition IMO Accurate Powders are no dirtier than any others and less than many.
2,5,7, & 9 cover the area of most handgun loads and are nicely spaced so that you can do most everything you want. Although sometimes a 6 & 8, might come in handy.
They meter very well and are dense making them good for loads in smaller cases.
I have not opened my Unique or 2400 cans in a long time or used 110/296 in favor of Accurate and Vihtavouri.