CLR is much faster with string manipulations. there are some things that cannot be done in TSQL
Regular expressions is one of the most common example, where it cannot be done natively, and is also much faster for doing string manipulations that could be done in TSQL anyway.
there is a great performance measure made by some of the top posters that compared TSQL to CLR performance wise, including Tally table measures, that showed a good example of a situation where CLR was faster; i
batches of nested find and replace are also faster. REPLACE(REPLACE(REPLACE(....kind of stuff.
also, there is no data from Microsoft which says that there may be performance improvements if the logic was implement as a SQLCLR SP rather than a normal C# business object.
also, just because Microsoft doesn't paint themselves in a corner by saying something is faster or not, does not make it false...they just don't say it because it may not cover every situation. "CLR is faster" is not true all the time.
Lowell