I have a D and D fatcat with the ghost pipe. After going through many mufflers and pipes on my Ultra last year, I have found the sound. I love it! It sounds great to me, and it performs very well.
I have the wrapped performance baffle and it sounds deep and mean. Many people comment on the good sound. They sell it in unwrapped as well and it is loud, but I have only heard it while standing next to the bike, not riding it and it sounds bad a$$. I am used to my wrapped one, and it doesn't seem loud to me anymore, particularly now that I have upgraded my stereo so it is very loud and clear, so there are times I wish I had the unwrapped when I am in a more aggressive mood. I bet it sounds awesome while riding the bike around town, but I am sure it would get old on a trip. They have a quieter one for stock engines ( maybe smaller than 110 as well) the concentric baffle.
As to the ghost pipe being clean inside because it is not passing any exhaust , I took the suggestion of someone else on the forum and painted the inside of it with paint and it looks great. They said to clean both sides with brake cleaner first and paint the inside of both of them so they would match and they were right. I used high temperature black from an auto parts store. It is relatively flat
Here is what I used:

and here is what it looks like:
