@williamatics Whoops, yes I totally missed your submission – thanks for pointing me there!
Wow, your tank has turned out splendidly. For the most part surfaces are smooth, edges are crisp, and details are lovely. Also there’s some clever modeling techniques in there 😎. I’ve a couple technical notes:
1. One piece on the back isn’t modeled for subsurf. I imagine a simple oversight.

2. There’s some detail “decals” on the back that have overly sharp edges compared to the smoothness of edges everywhere else:

And finally a more subjective note, since this is a concept vehicle: There are areas that feel under-detailed; too simple by comparison to other areas. Like the base of the tank and hover engines. Next to the more detailed areas, these feel plain; they’re begging for some extra flair imo.

Those are fairly minor notes though. All things considered, I’m quite impressed with your result! It’s an A for the week, easy.