The pipes with all of the internals removed don't sound good to me. Not like a good set of Termignoni pipes would. They're usually just loud and obnoxious.
But a half-mod sounds much better than stock and isn't hard to do. With a bandsaw I could modify those pipes in less than half an hour. When I did mine, years ago, I spent several hours on it using a hacksaw and muscle power. I bought a pack of about a dozen blades, since they tend to wear out cutting steel like that.
If you cut off three inches and remove the center tube, you get the good sound without too much work. You just need an electric drill to make holes to reattach the endcap and a pop rivet gun to attach it.
The disadvantage of this method is that you don't get much of a weight loss.
I know this is blasphemy but my dad went through the same thing with his.... dun dun dun... Harley. Cutting down the internal baffling sounded much better then when he completely cored it out. Like Scott said it just became loud and obnoxious, but it was too late and he had to wait until they came out with exhaust utilizing the O2 sensor on his model.
