I have the Stowaway cantle and two of their pommel (one regular, one “deluxe” pommel with the water bottles) - I prefer the cantle bags. The pommel bag has a lot of straps that don’t really seem to go anywhere, like it’s up to you to just figure out how and where to strap them on.
The cantle bag fits very nicely around the seat without any interference or bouncing, and there are a lot of pockets and places to stuff your “stuff.”
Lots of pockets in the pommel bags as well but, like I said, I’m not crazy about the randomness of the straps. It seems like I can never really get it to fit “snug” to the front of my saddle. I ride in two different saddles; one is a Tucker Cheyenne (with horn), the other is sort of a “Western endurance” with no horn.