I think the point is that those with P4/P3 will have renders that up front won't look as good as other apps including P5. If you set up a pose in Poser then render in Lightwave hasn't it ceased being a work of Poser really? As for post work, I think they are thinking mostly of PS and Painter, much harder work than just rendering in a different program. I think it's a way of evening the feild a bit. Just my $.02