For those with a USB microscope it might be worthwhile to look at your stylii. Take some pictures and keep those along with any information you have about your cartridges' use. This can be a reference / baseline for comparison going forward.
Also worthwhile is discerning the stylus geometry or shape of your cartridges as this can have an impact on wear potential. Shape info is often available from the manufacturer or sometimes via Web search.
My Benz Micro LP S with Micro Ridge shape and only a few hours on it. Frontal shots are also helpful.