I have ridden both-
the Zero has a smaller cutout and more padding. I found that the padding actually closed the hole up as is started to break in, so I went with the Falcon, which has less padding and a large cutout.
It did cause some seatbone soreness for the first two weeks I rode on it, but once that went away, it was pretty comfortable. I could ride on it for about 40 miles with no problem, but it would start to irritate me beyond that because it is a very pear shaped saddle.
I liked it a lot because it's one of the few lightweight saddles that's actually wide enough for my seatbones. I ride an an-atomica now because I could not find anything else that I was comfortable on for high mileage rides.