I'd think that if you're having system problems with RayDream, you'd probably be in for a bunch more with the more complex LightWave. 5.5 might solve your problems, but it might not.... Carrara seems (from what I've seen) to follow a similar (if not identical) logic to RayDream; gday's comment about it being easy to pick up is probably from a RayDream familiar vantage. Since Carrara is a MetaCreations product, it does seem (from what I've read here) to work pretty well with Poser. Good luck!