Nexbox has the board UPSIDE Down within the casing.
That to me is a bad design due to the fact that Heat Rises.
The casing is also smaller than other boxes.
Users often misinterpret the function of cooling to be making their box/device run cool, or as cool as possible, which is never the [sic] case. In reality the main objective is ensuring a safe operating temperature range. As long as cooling holes do this, the objective is reached. Holes on the bottom generally result in lower levels of dust ingression to the device and avoid the opportunity for liquid spill damage so in most consumer products would be preferred to holes/vents on the sides or top.