I'm thinking about doing this as well. Prefer it not to be any louder though. I would also be interested to hear about others opinion on this.
As I had just swapped mufflers last week what I noticed is that the heat from the cat is (was) gone. It's still cool outside so you really can't tell.
The bike ran fine around town and very quiet, actually a nice tone. NO change in the tune I am using.
On the freeway over the mountain passes the engine seemed to struggle and take more throttle than the Fullsac mufflers I usually run.
I put my Fullsac mufflers on for the last trip (about 700 miles) and will leave them on. I like a deeper tone and better seat of the pants feeling under load.
The engine doesn't seem to struggle as much passing trucks or pulling the grades compared to the other bikes with us.
JMHO of course, but I had a set of new take-offs I wanted to try.