I'll give you a little bit of the backstory on this.
We had it for vBulletin 3.8 and 4, it stopped well obvr 2 million bot registrations in three years, on the 5 or 6 boards it was on. Without even one single bot registration success. But, vB5 came out, and we saw we didn't want any part of that so we never released this for vB to the public.
Now here we are, about where we were back then, except this is xenForo and we doubt they will screw their product up like vB did. So, here we go.
On two of my sites so far, this has stopped around 4,000 bot registration attempts in just three week, and nothing's gotten past it.
Best part of the Spaminator is, it is impossible to interfere with or even annoy any legitimate human. Because they'll never know it's there. Plus everything is logged, so you can see what it catches.