I have been using the Grex Tritium gravity-feed airbrush for several months now with a 2HP compressor (1 is probably enough, but because of an out-of-stock situation, I was given the 2HP at the same price). I am very pleased with the Grex, especially compared to the Paasche siphon-feed I had been using with a very small compressor. Coverage is much faster now (I suspect that is more the compressor than the airbrush). Note that this is an airbrush, not a spray gun. Unless you have significant volume, Grex does not recommend the gun it sells for chocolate work. For one thing, the paint cup is quite large and therefore requires a lot of cocoa butter--and I can only imagine how lengthy the cleaning process is. I agree with all the upsides and downsides mentioned above in regard to gravity feed, but with siphon feed, I had to stop and heat up the paint container every few minutes--now the situation is much better. But, to be honest, there is no getting around how difficult spraying chocolate through an airbrush is; after all, the instrument was never meant for this purpose. I do have a mini-spray gun in addition to the Grex (both are hooked up to the compressor), but have not used it very much because my production is fairly low and it is quite difficult to clean. I have the 0.7mm nozzle on the Grex (the largest they make). I'll be glad to answer any questions you may have about the Grex. As was pointed out, their customer service is excellent--above and beyond the call of duty in my experience.