and if your making models for sfc III I have found when exporting anything above 3.1 can have and issue on the overall effect of your meshes if they are unified.
But it does depend on the complication of the mesh..
in 3.1 your mesh can be as complicated as it likes, but it will retain all smoothing groups etc, outside of this say using max 5 then exporting to .mod, even if your smoothing groups are sorted can sometimes resort to an ugly effect, thats what happend to my gagarin i worked out last month.