I have not made the leap to an airbrush yet, either. I use Tamiya spray cans almost exclusively, and while expensive, they have a nice spray pattern, are consistent, and there is a broad range of colors. Tamiya is not available everywhere, but mail order is always an option, I guess. There were SEVERAL times on my latest model where I wished I could have had the tight control/pattern of an airbrush, though. I ended up doing a lot of masking, and you do waste a fair amount of paint. Just my 2 cents.
Even with an airbrush you are going to do a lot of masking unless you can free hand a pattern like MERDC camo. I've been thinking about doing a camo pattern like British Urban in Berlin on an Abrams decked out for fighting in a city like NYC but mainly in shades of concrete and asphalt (no 50 shades of grey jokes please). I got an excellent airbrush, a large compressor and I know I'll be masking like a mad man. I've freehanded camo but the edges always always seemed too 'soft' at scale. Especially on 1/72 scale aircraft.