from a former AAV crewcheif, looks pretty darn good. A few minor notes...

first, you have the water jets (buckets) open in the back. This only happens while in "water" mode, which if you are traveling on land you would not be in as water mode closes up the cooling air intakes for the radiator and directs all the engine coolant through a "contact cooler" on the bottom of the hull where it cools the engine coolant by transfering heat to the outside water while afloat. Basicly, if you are sitting on dry land, in water mode, you would overheat the engine within 5-10 minutes. So, the short of it is those jet deflectors should be closed.

the other is you have the bow plane partaly deployed. This should be tucked completly against the hull.

Now, if you were to place your model on a base with sand and partial surf, as though it had just climbed out of the water, then that would solve both of the above issues (the driver would be about to swich to land mode, and is in process of retracting the bow plane), PLUS that would take care of anothers comments about the lower hull/ tracks being too clean. You can use some Future (Johnson Kleer) to give the lower vehicle a wet look, and paint on using the future water splashes, and areas where the water is draining off the vehicle.

again, great looking model! Thanks for sharing!
Andy