I don't think an external OBJ would make much difference if you're on Poser 5. How big is this thing - what's the size of the CR2, and does it perhaps have lots of big textures? Karen's point about texture paths is a good one, and I'd deinitely run Correct Reference over it. However the slowness you experience when moving the object indicates that it's resource hungry, and there may not be much to be done about that.