That's correct. The T-splines people say that it's able to duplicate any nurbs surface exactly, and any catmull-clark surface exactly. This of course must be under the right conditions, and with enough CPU power to handle complex objects. A t-spline is probably carrying more overhead than either Nurbs or Subd...

jonah

Hi Tyglik,

Thanks for correcting my errors. Guess I need to do my homework more properly ;-)

Anyway, for those interested in the topic of the convergence of NURBS and SDS the article on extended subdivision surfaces is higly recommended. It seems like ESUBS offer even more possibilities than T-NURCC surfaces (t-splines).
Here is the link:

http://portal.acm.org/citation.cfm?id=1138455

Happy modeling!!!