Alan;
I've been experimenting with both the airbrushes that HF sells. The plastic one that is similar to a Binks Wren and the double action one. The cheaper plastic brush isn't worth the money ($7.00 on sale) if trying to get good results on a model. This is one case where I'd say that given the choice of a spraycan or this brush to paint a model with, use the can. The spray pattern is extremely large, even when almost closed off. It would make a good scenery "toning" brush. I don't know if any Badger parts would fit it. I do know that Passche tips don't.
The double action one absolutely surprised me. It painted extremely well, and gives an extremely smooth finish. It appears to be a Badger clone, but I don't remember the model number. I do know that the tip and nozzle assemblies can be replaced with Badger parts.
I have even gotten to where I use it more that my Passche now. The kit comes with a jar and a cup. My only complaint about it is the cup has a straight "pipe", and not curved like the cup on my Passche. The cup as a result stays close to the hose connector. I'm not used to a paint cup being in that position, and it seems a little awkward.