Hi!
I'm back (for a while ;)

This weekend I wrote a new beta of subdiv script. Yes :) I finally did it! :)
This version is very unstable, but it works much better with extraordinary vertices. C1 continuous on extraordinary vertices, and C2 on ordinary vertices.
It doesn't support triangles in hq mode yet, so you need to use quads only.
Of course some surface issues may occurs. I think there may be some bugs.
Also I plan to write an optimization block, which can stitch separated ordinary quads to one surface.