I started using Swiss a few years back. It is all I use in my sidelocks and older #11 cap in-lines anymore. I believe it is supposed to be 15-20% more powerful than regular black powder. I find it to be some what true. I have been able to reduce my charges since using it. Have never had a problem with hang or misfires. I get better accuracy since using it as well. Clean up is about the same. However Swiss seems to leave a drier, crustier fouling than regular black powder. You will pay a few dollars more a bottle , but I believe it is worth it.
I find the volume vs weight of Swiss are closer than any other powder I have ever used.