I would say MAX2GS. You can find it in the download section. With it you can export your whole scene. Terrains and blocks all created for you. Even object placement.
and what about A7 , it use mdls too ??? ,we want one,complete exporter for 3dsmax (9-too) ,whith animation,textures and no problem with exporting . (i was reading about FBX format ,but still problems with)