No. Important is map layout, not models/textures.
In case if you are experienced level designer, then use unity engine, where you can import anything you want.
Yes, I reckon this game would be much better if we could make bigger, more realistic maps, with better buildings that we could go inside and explore.
I reckon that blocky maps such as most maps on there make buildings impractible, as walls are too thick there is no detail so it is harder to find your way around.