I'm going to go with the V&H Power Duals. I like the way they look and I already have 4" Rinehart Slipons on the bike. I like the power on the bike and am afraid True Duals or V&H Dresser Duals will lose me some of that. The True Duals will give me more sound, but I think the V&H Power Duals in combo with my Slipons will give me "enough" sound. This is the second set of slipons I've had on the bike, the first were Python Predators, very unhappy with the sound and I feel that It cost me a lot of power off the line and when passing. When I had those put on, I had to get a download, about $150 from the dealer, but when I switched to the Rineharts, he said it wasn't necessary to download again, When I told him I was going with the V&H Power Duals, which I haven't done yet, he said didn't need any additional download either. I also like that the Power Duals are about half of what it costs for the True Duals, of course, if I hadn't added slipons, I might have considered a complet Rinehart True Dual Exhaust system, but I do like the idea of slipons and being able to change them as age and the mood hits me. This is about as mechanical as I get, sorry I don't more technical answers for you. Enjoy the ride, I just had mine out, and it was a beautiful day!