I use Carrara for rendering some Poser scenes, and I think it's definitely worth it. I don't do much network rendering, but the speed difference between Poser and Carrara is dramatic, especially if you're looking for rendering large scenes with complex lighting. I'd be willing to say it's twice as fast on comparable quality scenes, but I don't have actual benchmarks to prove it. Carrara's raytrace engine is one of the fastest I've used, with the exception of a few higher-end renderers that I've experimented with. If you have ANY raytraced reflections or refractive materials in your scenes, then Carrara is going to outperform Poser by much more than 2x the speed, and with better final quality to be sure. Carrara 5's AO is definitely faster than Poser's, and you're also getting true SSS with Carrara. The only downfall so far with Carrara's SSS is that you can't define it with maps. For instance, if you wanted more SSS on certain areas of the figure, but less on other parts, you have no real way to control this with greyscale maps like in Poser and some other apps I've worked with. The SSS is homogeneous, defined by the model's structure itself. This isn't really a show-stopper, since the SSS still works nicely, but it doesn't allow the level of manual control I really wanted. Carrara does have procedural shaders, but I still think Poser's node-based material room can possibly do more if you're a math guru who can figure out complex node trees.