Great first effort! You'll need to watch your mix for the airbrush...it's spattering at the edges.
It took me a LOOOONG time to get over the fear of an airbrush but the results can be awsome. Just look at some of the work these folks put out here at Armorama.
Your second pic (close up of the left side [spare track area]) shows what I'm referring to: it appears that the mix was a bit too thick, but not by much. One method I found that works decent is to mark (either on the model or in your "minds eye") where the camo is going and paint the outlines first. Aim your spray "in," that is, if you have a wide band, paint the left edge first aiming towards the right....it'll give a cleaner line.
Did you use enamels or acrylics?
Use this Jagdtiger to play with different mediums (and get it ready for the dreaded diorama

).
Mike