The obj format works well, you just need to rescale it. The only pb is the memory needed. I export sidney g2 with the formal dress and hair, max9 hasn't been able to render it (blocked at 2Go of required memory).
But we could expect poser to export at the up to date 3DS format. For information I tried on an old version (3.1) and it didn't work. May be the 4 was the good.