Not sure if I want to revive this thread, but here goes:
Using an airbrush is just like using a paintbrush. Sometimes it looks better, otehr times it looks worse, as with all other techniques and effects. There is just one thing I hate: (well not hate, but strongly dislike) aurbrushed
OSL. No, not all
OSL made by airbrush, but when it's either overdone, done wrong, or just sprayed on on literally every single weapon. I personally don't think spraying a white blob at a Plasma Pistol makes it look good. Here's an example; Awaken Realms. I normally love their paintjobs, they look excellent, there are only two paintjobs I think look awful (but then again, so is everything I paint, I can't really judge)
Look at that picture. Lovely bikes, right? There's just one thing... All bikers have a blue/white dot painted over their weapons, regardless of whether it is a Plasma or a Bolter. That is just... it shows that the painter, although very
very competent, missed that Bolters don't glow like that.
That's another one. I mean... what? Are those highlights?
OSL? Absolutely nothing looks like that in real life. Why did they feel the need to paint white blobs on the top of all surfaces?