Hello Bruce. Fancy running in to you here
I've been running retipped cartridges with different than stock cantilevers and styli for about 7-8 years now with very good results. IMO, it is truly a great way to achieve biggest bang for the buck especially with escalating cartridge prices in higher end models in the past few years.
My first forays were with Peter Ledermann at Soundsmith; he retipped a couple of Denon 103R's for me, both with ruby cantilevers, one with his standard line contact stylus and the other with his OCL (Optimised Contour Contact Line) stylus, which pretty closely resembles the Ortofon Replicant.
Both of these cartridges were also rebodied, one in aluminum and the other in ebony, and they played well above what I had invested in them. They were grossly superior to stock 103R's. I had used the ebony bodied model with stock cantilever and stylus before retipping it-the body alone was a significant improvement and the retip with better cantilever and stylus also offered a major performance boost.
After that I had Andy do a couple of Ortofon MC 20 Supers for me. The nice thing about Andy is that his charges as standard include rejuvenating/re-working the suspension which I do not believe is the case with Peter. He did one of my Ortofons with a boron/microridge and the 2nd with sapphire/microridge. They were also a huge step up from my MC 20 Super with standard aluminum cantilever and its stylus.
The last cartridge I had Andy do (and which is currently in use) is an Accuphase AC2. This cartridge originally featured a sapphire tube cantilever but I never heard it stock as I bought the cartridge off Ebay without cantilever and stylus. After 7-8 years and a number of retips I've come to the conclusion that I prefer the sound of boron cantilevers. They just sound more natural to me, very smooth but also very dynamic and I think that boron also is the best in terms of reducing surface and extraneous noise in playback but that is just anecdotal. Boron is also, in my opinion, a bit more "mid hall" in presentation in my opinion; I think listeners that prefer a more front row presentation, and are possibly a bit more detail oriented in their listening preferences, might well prefer sapphire or ruby.
There was a group buy of Namiki boron cantilevers with microridge styli that was organized by Warren Jarrett at the Hoffman forum and I participated in this and picked up a couple of those (and then an extra one after that as well from someone who ended up not needing it), one of which was used to do the Accuphase, which I sent to Andy along with the Namiki cantilever/stylus. The Namiki boron/microridge is extremely high quality; I'd guess that it is stock on some very exotic & pricey cartridges these days.
Within the context of my system, anyway, the Accuphase is a destination cartridge, so much better than the other cartridges I've used that I have no desire to upgrade at this stage. Also an almost perfect match with my phono stage.
But I do have a couple of the Namiki cantilevers sitting here and am giving serious thought to sending my AT 33 Mono (which probably only has 50-60 hours on it) off to have one of those attached to it. My guess is that it would totally supercharge that cartridge, which is already very good even with a relatively modest aluminum cantilever and nude conical on it. There's only one way to find out and I'll probably go for it at some time. The AT certainly won't need any suspension work so I may send off to someone else. There seem to be quite a few retippers surfacing globally now, many of whom have very good reputations.
Say hi to Adrian for me and if you're ever in London stop in!