The thing to keep in mind about dithering is that is tends to create the illusion of a rough texture, and when pixelling things like metal and skin and other, similarly smooth surfaces, it generally something to avoid. That said, I think the dithering works quite well here for a few reasons. First, the contrast between shades isn't super harsh here, and as such, the image retains a pretty smooth, soft look. Second, I'm no tank expert, butfrom what I've seen they aren't generally made of super-slick, shiny, smooth metals; their surfaces usually appear rather matte, flat. Lastly, this is just personal oppinion, but... I mean, tanks'd take quite a beating in the field, don't they? Honestly, I don't they should have that "super shiny clean and new" look, anyway...
Apologies for rambling. I'm not thinking so great atm.

I think the new one is a pretty vast improvement over the previous, which was better than the first, so... good pattern there. Keep it up.