Quote: "Since the engine runs on DX, .x models textured by .dds is the best way to go, speedwise, because directx supports these formats directly. I've used models MUCH larger than what you described, and usually they take only a fraction of a second to load."
This is not true, although I see your reasoning.
DarkGDK does use DirectX but it has its own file format(dbo) which is the most efficient.
Unless you have come across an instance where dbo took longer to load?
It's important to note that the x file loading time issue does not happen on all machines, it takes forever on my laptop but not on my desktop.
It is advised somewhere in the official documentation that you should save all your 3D media as dbo before shipping the product.