Real world life expectancy of a high end cartridge?

I've had cartridges that made it easily to 2,000 hours.  I keep my records clean, which might, at least partially account for the lifespan.  Much of my collection has been treated with LAST.  Anyone who has used LAST knows that it is not true that it is merely composed of freon and will evaporate completely.  Put some on a record and you will see the residue.  At the first play of a record, you might even see fine "dust" that is the residue from deep inside the groove.  A LAST treated record will be less prone to building up a static charge, and if you run any sort of brush against the surface, you will notice a much lower level of friction--it has lubricating properties.  Having not done any sort of rigorous testing, I have no idea on whether or not LAST improves record life or the life of the cartridge, but, to say it does nothing is flat out wrong.  

A literature review and survey of stylus life was published on The Vinyl Press in mid-2019. Lots of detail, research, etc., in an article entitled "The Finish Line for Your Phonograph Stylus…" Reasonable reference to keep at hand. Interestingly, cartridge manufacturers have all gone to longer stated life than they did 30-40 years ago. Proof positive of this is with Ortofon (have used them since the 1980s) that back then in their owners manuals (see the VinylEngine) stated definitively 500 hours of life, now for the same diamonds, 2000 hours life. I personally find that disconcerting. Ortofon has refused my requests for research to back up their longer hour claims and other details when I have pointed this out to them.

Whether a stylus is high-end or not makes no difference. They are all fabricated from diamond (unless you use ruby stylus tips). Diamond is the hardest known substance on earth. The cut stylus can be from "aligned" diamond, meaning that even diamond has vector properties. Aligned along an internal crystal lattice face, a diamond will last a bit longer (spit-balling 10% longer) than those cut without that alignment. High-end cartridges are more likely to align their cut stylus in such a way.

A crucial aspect is VTF. If a cartridge is designed for 2.3 grams of VTF, it will not last as long as one designed for 1.8 grams. Shure back in the day did measurements on that, if you do a search. Finally, a diamond stylus has only a small contact with the vinyl, and I’ve seen it calculated what the force is for that small cross section. Its reported to be a surprisingly large load, actually.

Maintaining very clean records also prolongs stylus life, since the diamond is not "track grading" thought dust, including diamond dust, oils, and other debris. Ultrasonic cleaning and vacuum cleaning and resleeving is recommended and its how I do it.

Based on all that I have read, I am dubious of claims of stylus life beyond 1,000 hours of play on very clean records. I’m in the 700-800 range myself, tops, and I use high end cartridges. So I might recommend having the stylus examined by someone who knows what they are doing at that time of play. The change in sonics is ever so gradual, and we are used to it, how does someone really know their kit lasts 2,000 hours if they don’t have the stylus periodically examined?

Finally, I use Stylast. I have never seen published research that validates the 10x in extended stylus life. The best way to vet that is to show a photomicrograph of a worn diamond stylus at whatever hours that did not use Stylast. Then to show the same type of diamond on another life tip at 500 hours, 1,000, 1,500, 2,000, and so on to 10x life. While I use their products, that company has never really backed up their claims in a meaningful way. If I am wrong on that, please whomever knows post something to support their claims. My point, I want to know definitively.

Here is what the company says, this write up is fine, but in my view they need to publish the proof.

I have an XLM that’s 40 plus years old and sounds perfect.

Where is the patent for Stylast:

A Company that has a very healthy turnover can carry out a lot of R&D and Testing on their products.

I don't live and breathe Stylus Life, I accept that if I get close to 1000 Hrs without a catastrophe having occurred I am home and dry, from this point on, I will be wondering how my maintenance of the Vinyl and Cart' and my overall usage has affected the Stylus.

From a few hundred hours of usage, my experiences of undertaking a inspection has shown there is unwanted Micro Debris collecting and entering the Cart' Housing, by a 1000 Hrs when viewing the Stylus and as far into the Housing as can be achieved, the collection of Micro Debris is very concerning, as their is no doubt it is collecting on parts with a critical function that the Cantilever is attached to.

I have spoke to professional services about this contamination collecting, and it said to be lifted from the LP and airborne.

I know one case where a metal dust has been responsible for one channel being detrimentally affected by the contaminant being on the Coil and was not a repairable condition using the original coil wire as the rewind material.

Stylus Wear is only one consideration that can be detrimental to a Cart' maintaining a high level of performance, if the Cart' has been placed as a device with a importance and value, it is worth having the Cart' inspected by a professional service at 500hr intervals and cleaned if required, at 1000hrs this can also include a stylus inspection. It would be great if a professional service made this service a well known option with a accurate overall fee offered inclusive of shipping and insurance, it might encourage others to budget it in as part of Cart' ownership. 

If a Company were to make claims for a usage life of a part that is beyond the commonly seen guideline for the part in questions usage life, it is quite possible they can back this up.

What might be the case is that the Testing is planned to be a success and the figures being made known, are not produced from a everyday usage scenario, the failures of the Cart' owner might be eliminated and exposure to airborne contaminant might also be a factor to be eliminated as a impact.

A Cart' Stylus could be tested on a perfectly cleaned, purpose produced Test LP, with a Groove produced that enables a continuous play.

The environment the Test is carried out in can be controlled and filtered to ensure the airborne contaminant is not present.

It can not be said that the Stylus was not in contact with a Groove on a rotating Vinyl LP Pressing and that the Stylus could not last for a period of time as being suggested.  It might have lasted longer, but the Company chose to reduce the figure allowing for real world scenario's