Why so many different tools?

 

To follow up on the above, the principles of using an airbrush and rattle can are basically the same; both are paint being propelled onto the model by an air source and you start painting each pass off the model and finish off the model.

 

Like the Rev, I only recently switched from rattle cans to an airbrush.  I usually only used a rattle can for gloss paints on the NASCAR kits I built and flat white for larger space and science fiction kits.  I got fairly decent finishes using a rattlecan on the race cars that I built and good coverage on the sci-fi/space kits.  I still use a rattlecan for odd Duplicolor automotive colors and some priming since I don't want to try to decant and I think the finish is similar to what I would get with an airbrush.