The way I think about the whole thing, this is not about making something different; it's about making something good. Tone is the aim here.
But even accepting the "more different" reasoning for voting one way or the other, the hybrid is actually the "more different" option IMO. It would be far different than any neck humbucker Duncan makes or has ever made, both tonally and techincally (having heavily mismatched coils, and in the neck position). We know what hybrids are like; the tone is somewhat predictable, and extremely desirable IMO. I think a lot of people would love this pickup, and it would add a significantly different flavor to a lot of axes out there.
The Zebro, on the other hand is only different in that it will use trimmed-down bobbins instead of full-length bobbins. We have no actual knowledge of what advantage this could possibly offer. It's nothing but a possibly meaningless technical spec for the Custom Shop to be held to. It seems like it's trying to be different just for the sake of being different, not for any specific tonal reason...and even then, it's not really that different anyhow. It's just an adjustable version of a Mustang bass pickup. How different could that really sound than other options out there? And if it does sound that different, will it really be in a good way? I certainly am no fan of hum-canceling singles, and I know I am not the only one. How many people would actually want one of these things for any reason other than just screwing around? I.e. who will buy it because they think it will actually give them something tonally that they can't get now?
The hybrid would also sell better to the general public IMO, and would make the '59/C into a factory set. It has far better chance to make it as a potential addition to the standard catalog (which would be a first for a forum-designed pickup). I would take far more pride in having something that we designed actually accepted into the standard Duncan catalog than I would be to have designed some one-run-and-done pickup that ends up in only a dozen guitars throughout history.
Also, the hybrid option includes a possibly awesome bridge pickup that is different than the current '59/C: a slightly thinned-out, scrappier '59/C Hybrid. Yummy.
The hybrid also retains the stock "sleeper" look. That matters to me, and maybe to others too. I'd probably never use something that looked like the Zebro in any of my current guitars.
Not only does the hybrid fill a much larger hole in SD's catalog in terms of TONE (which is what it's all about), but it would benefit them more in the business sense, as they could probably sell loads of the things to "regular" (i.e. non-Forum) customers. I.e., we could give something back to the company for dealing with our idiotic asses at all.