When you first begin using a new gadget as a hobbyist, whether it's flocking, new brushes, or even a new sculpting medium, there is always a learning curve that simple instruction can't bridge. The difference is time spent behind the wheel as it were. I've Just finished putting multiple coats of vomit brown on my Space Marines, and I can definitely see myself using this airbrush to further my goal of paint domination. I wouldn't use one for single pieces, but as a tool being used at a large scale, it really decreases the time investment and increases the quality of the paint coverage.
I've learned that gloves are a must(I stole a pocketful from a hospital room while visiting my wifes' gram over the weekend, let's hear it for petty theft!). I clean that bad Larry after every use too. I had to learn that my teeny-tiny compressor can't handle the thick Citadel pigments, and they need to be thinned. This hobby that started as a social activity has really taken on a life of it's own. I've delved into old interests that I thought I had forgotten; being an artist, doing concept work on my armies, model work for conversions, I love it all!