I am no fan of The Vinyl Engine BUT, there was member called Ray, who did good reasonably Scientific Method sound study into this. His study was good but, lacked much verification and peer review. However, his findings were interesting and to some degree did give some clarity ...I would first suggest finding the work and reading it, but his findings were quite interesting and would stand as good reference material.....In a nutshell, he found ...under 2g VTF and with good clean records ...looking mainly at an elliptical stylus ........300hrs showed detectable, but non damaging wear, which was tough to hear, 700hrs showed more wear which you might be able to detect on a good system, but would not damage......1000 hrs here was the point where you could find that you could hear the changes and you might well want to change this stylus but the "flats " were a good size but, with some styli you could go further.....now that would depend on the diamond.... Other shapes: for a conical equate 1000 hrs to 600 ....for the line contact family equate 1000 hrs to 1500 maybe 2000.......with more exotic shapes 2000 up to maybe 3000. A lot depended on how clean records were , how well you align and the correct tracking force plus how well you used good azimuth, and how well you matched effective mass to compliance etc but, his work does have some scientific credibility and could be a good guide.......it also made some senses as to that which manufacturers said ( and with some what they did say but not clearly ) ....What he did lack was repeatability however, his work had matched what was found in the better literature and the more often repeated findings of reasonable user research in the area..these factors would go a good way to give the data peer review and repeatability which many statements on fora often lack.
