Very different experience with the RE X-Pipe here. Way more than 5% increase in sound. Deeper tone, more pops/burbles, and more volume.
Just like the cans themselves, I think there may be differences in X-Pipes brand to brand.
johanness has the SS X-Pipe. SeanK has the SS X-Pipe as well, and we were were talking about X-Pipes awhile back and he said he didn't really notice anything when he added his to his SS Powerloops. (May help with flow, but doesn't change note at all.)
Small number of data points, but there seems to be a difference. The RE turned the Eisenmann Sport into a different beast. Still no drone, but it's got those nice (to me) notes and a bit more bark. I don't notice any rasp, but you might want to check the Full Spreadsheet and Comments in the first post
here, and listen as well. That will give other POVs from other ears regarding the rasp dimension.