Silo is great, but is dead. As long as there are just words from NC and no actual updates for years, the death remains. Pixologic development model is something completely different. I think VW will be a quite substantial "update" to Silo. :)
TheDaemon: that seems like a really difficult thing to get right. The regular edge-weighting for sub-d is a dissapointing affair in my experience, and the Pixar (Catmull Clark) algorithm is patented as you say. I imagine one would have to pay to integrate it into your application? Also, how bizarre is it that Pixologic…