I've used one for two years. It's very effective coaxing toms closer after the box or pot for locating/initial contact. Very effective.
However, it is hard to stow and carry in a vest or holster. If you have a pot that you like the clucks/purrs, they are easier to carry.
I think Lonzo makes one, too. Haven't heard it.
The Woodhaven is a true killer. Just a bit cumbersome to carry.
I don't want to sell mine.