Re-tipped stylus vs original manufacturer

I have only had a couple retipped cartridges myself.

One bought already retipped with about 50 hrs on it that I had owned the model previously. Also one I had retipped myself. Both sounded very good and very similar to the originals but with a very slight loss of the upper shimmer even after a few hundred hours time. I wouldn't word it that you can't or couldn't tell the difference but rather accept it isn't the same original cart so changes would be or should be expected. To what degree is the real point.

I'm usually more suspect of ads for retipped with zero hrs use claimed and put up for sale without knowing what you payed for. I haven't had much experience with used carts though.        

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

I’ve had a couple Koetsu stones rebuilt. They definitely reuse the old body and (usually?) the magnet. Everything else (armature, coils, damper, suspension, yoke, cantilever & stylus) is newly built. And they do a great job of it! Consistently great results. Maybe on the "Black" model they replace with a new one, but I couldn’t speak to that.

I believe Ortofon also takes this approach, though I haven’t had one rebuilt yet. Their info site on rebuilds used to warn that your body could come back with scratches from the work.

In both cases the "full rebuild" runs around 50% of a new model, sometimes a bit less. Koetsu won't penalize you for having the premium stones - rebuild cost is the same for any stone, though the diamond cantilever upgrade is quite costly if you opt for that. 

I recently had a Zyx Airy 3SB rebuilt by Steve Leung at VAS. I paid $250 for the cart knowing it needed a rebuild, and he charged $450 and I have a cartridge that now sounds fantastic. I talked to Mehran and the Zyx factory exchange cost was $1500. I'm sure that Steve's considerable talent does not make my rebuilt cart equivalent to a new one from Zyx, but it still sounds great at 1/3 the cost.

I have a retipped ZYX Universe IIX by Steve @ VAS and I can't really tell the difference. I have a more expensive Gold Note Tuscany mc, but the retipped ZYX Universe is more revealing/dynamic/enjoyable. So there you go.

All new cartridges have a very unique flavor profile born from the sum of all of its different parts and the way in which everything is fastened together. I don’t think you can except to change any one of these critical parts and have the exact same flavor profile afterwards. That’s not to say that it can’t come back from Steve at VAS or wherever sounding good, great, or maybe even better than when new, but I would expect it to sound different.

 I recently needed a rebuild on an Audio Tekne MC 6310. I’d just received a rebuild back from Steve on an older Audioquest and it sounded very good for the $500 that he charged. But I decided to send the Audio Tekne back to the factory in Japan where it was completely rebuilt by the craftsman who originally built it over a decade ago. The rebuild cost was $1000, twice what a VAS rebuild would have been, but I believe that the cartridge now sounds the same as it did when it was new. Not worse, not better, not different.