They finally arrived in the post from the USA. The finish was excellent and the bits and pieces were there, EXCEPT for the gaskets. It's odd that they don't throw those in the box. After all, how much extra would they cost?. Anyway, I spent two hours fitting them and lost a bit of bark off a few knuckles. By golly some of the nuts were tough to get off and hard to get to. At start up, they do rummble - a lot . I suppose its more of a deep bass sound. At idle, they're not too bad - still loud but not uncomfortably so. Taking off is when they get really LOUD. My first thought was that I'd made a mistake buying them but I'll give them a week or two and see how I 'adjust' to them.
Tomorrow I'm taking it to Procycles at St Peters for a tune and see what it does to the sound. If I decide to go back to the quiet life and refit the standard pipes, I'll stick the D&D's on Ebay. Watch this space.