I think that Kurt (OrionMystery) has one (not sure). The biggest problem with both of the Venus lenses is that the aperture is manual and if you shoot with the lens stopped down the view finder is going to be dark. Other than that I haven't seen any other complaints (but not many people are using them, and I think it's due to the aperture issue).
I would trust product reviews from people who paid for the lens verses people who were given the lens for free by Venus for a review*. There is a review at B&H where the user talks about the manual aperture but also has this to say:
The second issue is the working distance. The lens' 1:1 ratio distance is mere millimeters.. In other words if you want 1:1 you had better be ready to touch your glass to the subject (almost) and block all your light. The reality is that in the "real world" you will almost never be able to get 1:1 out of this lens. Only in a controlled studio environment.
Curious to know if that's accurate, and if so that would rule it out for me since I like going after active subjects. Edit: Yup, the working distance is under 5mm. Ouch.
*Not calling anyone out with that statement. I use to run a tech support web site (computers and networking) and lost count of the number of times I was offered free hardware and software for a favorable review...