Exbox - I've owned one. I bought it because it's the most out of the way. You can really see the rear wheel. It's centralized mass. It sounds good (subjective) and it is the simplest.
I have three issues with this quote.
1) "It's the most out of the way." - Um... no? It's larger than a comparable set of BoomTubes, meaning it's MORE in the way. It's more out of the way than, say, a stock exhaust or a direct aftermarket replacement (Zard, Arrow, Termi etc.). To say that it's the "most out of the way" is, frankly, bullshit.
2) "It's centralized mass." - Again, no. Comparing the options of Ex-Box - vs - BoomTubes: you've got a box that weighs more hanging farther off the back of the engine. Once again, it does a better job of "centralizing mass" than a stock exhaust or comparable system. But which is better? Having more mass closer to the back of the engine? Or having less mass hanging off the back of the engine and less mass overall?
3) "It is the simplest." - In what way? Horiz Pipe + Vert Pipe + Box + Baffles + Tips < Horiz Pipe + Vert Pipe + Crossover Pipe + Baffles + Tips?
ALL OF THAT BEING SAID!!!
My experience with BoomTubes on the DS1000 engine in my Sport 1000:
Mark is awesome, but it's gonna take you a while to get your Boom Tubes. They're gonna be everything you want them to be when you get them! But plan on having some delays. It's just a function of how they're made.
I (personally - this is "butt dyno," no real numbers) feel that the baffles in BoomTubes (should you ask for them) actually reduce top-end horsepower by a smidge. I have "medium-loud" baffles. The bike still has all kinds of grunt. That said, it gets a bit "winded" above about 6500-7000 rpm. It's nothing you're going to feel in "everyday" riding, but it's there.
I have the "staggered" tips, where the front one sticks out a lil further. That front tip is a bit ground down from taking hard right turns. Like "at the track" hard, not just "turned right at a stoplight" hard. So if you ride the bike in anger, be prepared to scuff the tip. Or have Mark adjust the length of the tubes/tips for you to avoid that problem.
Also: having "medium-loud" baffles, the bike is LOUD. I know immediately if I forgot to put in ear plugs. I can also tell if one of them isn't seated all the way.
Still: when I fire up the bike and hear the beautiful noise it makes? Yeah, I get a huge shit-eating grin.
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When I see a tunnel approaching and I downshift? Yup. Same smile.
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My vote: If you want sound and that last 1/10th of performance, get an Ex-Box.
If you want sound and the look of BoomTubes and are okay with sacrificing that last little fraction of power, then by all means get BoomTubes.