That is truly an INCREDIBLE castle, makes me just want to throw up my hands and give up on Bryce. I've had all those issues with rendering too, sheesh it drove me crazy. And yes the ram helps immensely, I recently upgraded another 512mb's and its made a world of difference. One little bit of advice, I think you should change the texture on the statues directly at the gate to a stone. Just the lion/type ones. And is your POV going to be what it is now or pointing down the center of all your poser figures?