I presume you're talkin bout that thing with the bladder attached to the call that you shake around? If so,no, I have never used one in a real huntingsituation, but I have played with them in the store and I guess they soundokay.
I'll share my opinion here even though you didn't ask for it
, and it is that I would go with a regular single reed or double reed and learn how to do a feeder call with it.
Truthfully, I don't rely very heavily on a "feeder" call and I'd feel a little limited if I had a call that would do only that. I mainly stick to quacks, content calls, and "tic-tock" type calls withouth the extended, rolling cadence of a feeder.