Here's something I wrote about this on another forum:
Hmm... interesting concept. I'd have to try it to be convinced, but it seems pretty cool if you happen to be good at playing it like the guy in the videos is.
It's too bad they didn't have a video of two of them going at once, that would be wild.
And what's up with that triple beater thing? I don't get it. I mean, I get it, but if you have a duellist on your right foot, why would you even want to have a single on the other foot? Seems a little redundant. Another duelliest would make more sense. But I suppose it has it's application.
I like the speedswitch thing though.
Seems to me that since the left stroke is powered by the stored energy of the down push, then when the pedal is in dual mode then pressing down on the pedal should be about twice as hard (enough energy for two strokes). For this reason, imo, a guy who is really quick as doing single strokes with his right foot would not necessarialy be able to double that speed with a duellist. But with two duellists, that would be just insanely fast. If I start hearing new extreme metal players playing "buzz rolls" their bass drums then I'm going to suspect they are using such a device.
With two of them the potential is just crazy. Imagine doing pretty slow and easy 16th notes @ 120 bmp (with both feet) and that would be like doing 16ths @240 bmp on 2 duellists, which is just insanely quick. I would think that doing that at about 144 bmp or something, which is still not that fast for the feet, would result in notes so close together it would sound like a buzz roll, or just a humming. I wouldn't be surprised if extreme metal guys started using this pedal to get an edge, but they might get flack for "cheating". I guess it is cheating kinda, but who cares? If it works as good as they claim, or even nearly as good, then not taking advantage of the technology, if you were so inclined to want that kind of speed and flexibility (like exteme metal players) would be a bit silly, kinda like someone who doesn't want to stop using cassettes or something, heheh. But then, a lot of guys out there are already so good with their regular pedals that they have no need to seek any to help them get any better. And at this point I'm just babbling like an idiot so I'll shut up now, heheh
rock on dudes.