I heard earlier versions of both speakers some years back at a So Cal hi fi show. Different rooms/Different systems - so it's not precisely an apples-to-apples comparison, but....
I preferred the Vivid. It was a more forward sound, but really boxless and airy, relative to the Wilson (which, by the way, were awfully good in their own right). The Wilsons seemed more "polite"(only on a relative basis, they were plenty dynamic compared to most anything else I heard, save the Vivids and the big MBLs) and might have shown better with classical music. IME, forward sounding speakers like the Vivid sometimes get a bit hard on massed strings, but I never heard that kind of program material on my audition, so I can't comment on how well the Vivids handle that test.
The two were different enough that I'd imagine most people would have a strong preference one way or the other. I liked the Vivid, but I'm sure that many would go the other way.
Marty