El Taino:
Makes a lot of sense Don, but, only if one is going to use it as a thinner agent. If I can get a one size fits all product, I'll be saving a lot more $$$ with a generic brand. Most of my modeling is done with acrylics, but I use the same paint thinner above for occasional airbrushing, cleaning the airbrush, oil washes and cleaning the tools involved. Now lets add that to the ''IF'' my paint of choice was enamel. If I was using Testors thinner for AB only and a generic one for cleaning, in my humble opinion, it would be even more expensive than using the cheap mineral spirit for everything.
Yes, it is a bit more expensive than using the generic for everything. However, I do find slight differences in the airbrush jobs when using the generic vs the Testors. Not a lot, but it does seem to go on a little smoother and thinner. And, again, when you actually look at the cost of the thinned paint, it is not a lot more expensive. Again, figure roughly a 1:1 thinning, and the cost of the paint bottle, and see how much you are actually increasing the cost of your paint by using the Testors vs the generic. An 8 ounce can does a number of models. In fact, the whole cost of paint AND thinner is a minor cost of building models these days, compared to the cost of the kit, and PE and resin aftermarket accessories.