The have two Quackhead calls. The J-Frame and the Timber. The J-Frame is molded off of the RNT Original, and the Timber is molded from the Timber. I have a J-Frame that I loved. Good cheap single reed call. My Dad has a Timber and I blew it some this weekend. I think it sounds about 85-90% as good as my Timbre Acrylic. Both calls are molded though, and they sort of 'rattle' like all cheaper calls do. Of course the rattling is part of the 'duck' that all call makers say is built into their calls. I guess I'm just spoiled by my wood and acrylic calls, they blow clean and rich. The 'duck' comes from something how it is blown.
I know this for sure, both Quackhead calls are DEFINATELY good enough to calls ducks, and lots of them! So are a lot of other calls in that price range. Since both Quackhead calls are molded from, and share the same reed set as, RNT custom calls, they also share the same drawbacks, just like duckbum pointed out. However, if you can learn how to drive a Quackhead without sticking it, you'll also be able to drive the custom calls. So it is a double-edged sword. If you spit, overblow, stick, you need to work on your calling anyway.
Just my opinion...