I owned a Wilson for a long time and used it seldom. I first installed it on a Prague Juzek and it worked pretty well. I sold the bass (still kick myself) and put it on my Voigt & Geiger. It was very dark, ala Fishman, but I think I drilled the holes too close to the strings. I haven't read anything on this, but I suspect that if you place the sensors close (like 7mm) to the strings, you will get a stringy EUB sound, and if you drill farther away (like 12mm) you will get a more woody, acoustic tone. I am doing OK with my first generation Schertler, so I decided to sell the Wilson. I was surprised at how many people wanted it, particularly from Holland.
The trouble with this pickup is that you are really committing yourself when you start drilling a bunch of holes in your bridge. You can't easily undrill 'em, and there's no way to decide upon the perfect spot unless you have your own shop, and can experiment on a large number of bridge tops.
Perhaps someone could contact all the "happy users" and get information on where their holes have been drilled (might be to personal!).
I got mine from Ideal Music in NYC. I don't recommend them at all, but you can get some good prices there.
Robobass