I love airbrushing i have taken on the Airbase brand and am more than impressed with thier products. I do a lot of weddings and i know i can guarantee that the make up will last through the whole day as it is heat resistant and water proof.
Also a little bit goes a long way, i am amazed at the coverage it gives, where i used to use all sorts of concealors underneath foundation to achive the perfect base, i know i can achieve a flawless base in half the time with my air brush!! Hope this helps!! I think if you are already established with your make up then go for it. I no longer need so many foundations of different textures?colours etc as i can specifically mix a foundation to match a clients skin tone with a few drops of two differents shades.
Airbase only deals with the base make up i.e. foundation/blusher and bronzer but you can buy airbrush eyeshadows from different companies although i havent done this yet as i love my MAC shadows and brush blending.
HTH a bit