Cleaning, less smoke, no sulfur smell and more velocity with less powder. I have also heard some say less hangfires due to the ignition of 777, although personally I don't have problems with pyrodex in either loose or pellet form. If you want to try 777 buy loose powder vs pellets, as mention the pellet form is down graded(diluted) by the factory by 15% for safety reasons. Meaning if you shoot 100 gr pellets of pyrodex and do the same with 777 pellets they are equal - you'll gain nothing in velocity but the benefits of easier cleaning, less smoke and smell will apply. Personally for me it isn't worth the extra to save a few minutes at the cleaning station.