I feel the Dansk is loud at idle and I'm not to crazy about the sound...a guy at work wanted to know if my car always sounded like a tractor.
....but get the RPMs up to around 3k and it sounds much better. Plus it seems to quiet down in the cabin around that 3k mark. It's easy to carry on conversations at driving speeds with the top off.
With SS exchangers and the SS skin of the Dansk, you get a lot of that "header ring" I think it's called. Which adds to the tone.
I should also add that I haven't heard enough 914's to know what the different systems sound like.