Re-tipped stylus vs original manufacturer

It is the opinion of a knowledgeable friend of mine that Koetsu just sends you a new cartridge. 

I recently had an Ortofon Quintet Black rebuilt with new cantilever on down

from Soundsmith but have yet to install and listen.  it looks

as good as new but until I hear it I can't speak on it, will check back.

As @ghdprentice relates, most moving coil cartridges are replaced by a "new" one.

I believe the old bodies are rebuilt and sold as new but it is possible that some are just dumped. 

Soundsmith does an excellent job of re-tipping cartridges but nobody can tell you what the sonic differences are between a factory cartridge and a re tipped one. You would have to compare the two at the same time or at least view frequency response curves. It is highly likely that most of us could not tell the difference but there is no easy way to prove that.