Okay.....
Ergonomically, it seems like a better idea than the standard double pedal because you won't have the lag on the slave pedal and it "should" give you more of the feel of a double kick drum with two pedals. I've never seen this pedal before seeing it pictured here and I've never tried it obviously. I think the "proof of the pudding" will be in how responsive it is. Is it smooth and musician friendly?
I experimented with the double kick and then the double pedal a few years ago and eventually decided that it wasn't for me, but for others that like and want that sound, I suppose this could be an option if it feels right.