Have used both Pyrodex and Shockeys Gold and to tell you the truth, can't see any difference between them other then the price.
Far as burning clean, IMO, from dirtiest to cleanest, the list would be:
1. Triple 7
2. Pyrodex and Shockey's
3. American Pioneer
I've not used the WhiteHots. Too, I'm wanting to use the Blackhorn as well and see how it cleans up compared to the AP.
Close to 2000 fps in the ballistic tables and sighting for zero at 140 yards (3.16" high at 100) the BDC Nikon has holds for out to 200 yards +.
For the area I hunt, 140yd zero would be very long. Most shots here are from 50-75yds. So my zero is 75.