So with OBJ output2 :)
Same results just better for Wings3D : normals (blue) and some faces curious like in the little base circular round right down )
Silo ok
Amapi 6.1 OK
Bryce 5 OK

Anim8Or (triangles)
Kerkythea (triangles)
Metasequoia (triangles)

Maxwell Studio a lot of triangles !

Shade 7.21 do not load (Buffer overun)

Image for Wings3D