Both powders have their good and their bad points. (like all powders I guess.) Pellets... I use Pyrodex RS pellets when I shoot pellets (which is only when I find them on sale). I get better accuracy with Pyrodex Pellets over Triple Seven pellets. Plus, I purchased two boxes of T-7 pellets and half of one box were duds.

Loose powder: Both work well. I get better accuracy with Pyrodex RS but it is possible to find a load with Triple Seven. You just have to keep looking. I find with Pyrodex I get more consistent accuracy. Now to explain that. I do not get as many fliers with Pyrodex RS and also the groups stay more to the POA from range time to range time in all kinds of weather and temperatures. I've had Triple Seven really make me do some head scratching on a hot day as to what went wrong with the accuracy of the rifle.

Cost: where I live, Pyrodex is a couple bucks cheaper a pound.

Swabbing: I would much rather swab a rifle shooting Pyrodex RS then Triple Seven. The fouling is softer, easier to pick up, and pull out. Granted the patch with Pyrodex is filthy, but that just tells me I pulled a lot of it out. Also I find I can shoot more rounds without swabbing shooting Pyrodex RS. With T-7 I always pay close attention to the swabbing, and slow way down when I get near the crud ring. I have stuck patches in that crud ring. I also have to scrub harder to make them come clean.

Clean up: About the same. I am not sure about everyone else, but my major clean up time on an inline is not so much the barrel. Its the breech plug threads, the bolts, striker, breech plugs, and parts. The barrel normally comes clean. So they are about even for clean up. I might have to run one or more patches down the barrel with Pyrodex. Big Deal!

Power: Triple Seven is more powerful volume measure to volume measure. But that means nothing to me. I adjust volume measures.

Between the two.. I like Pyrodex. Even though it is more corrosive, and you have to clean your rifle that day (which I always do) I still like the stuff.