I find that programmers who do not work with AAA engines generally have little concept what maps in an FPS game actually are. When you play Doom or Unreal, you aren't just running around in a big polygonal mesh. Map geometry uses brushes, which are an entirely different kind of geometry. It is with brushes that BSP, fast collision, and occlusion can be performed. These operations are impossible or impractical with arbitrary polygons. 3ds max is only a suitable level designer for very simple games that don't push the gfx card limitations very far, or that have no advanced visibility culling.
In a level editor, you create your map walls, floors, and large shapes with brushes. Then you use meshes, created in 3ds max or Maya, to add details to the scene. You don't want to go through and model every little detail uniquely. Instead, you rely on a library of pre-made meshes to place throughout the map.
HL2, Doom 3, and UT2004 all work this way.
In a level editor, you create your map walls, floors, and large shapes with brushes. Then you use meshes, created in 3ds max or Maya, to add details to the scene. You don't want to go through and model every little detail uniquely. Instead, you rely on a library of pre-made meshes to place throughout the map.
HL2, Doom 3, and UT2004 all work this way.