I could be wrong about this, but in my own personal experiences I have found many Moving Magnet Cartridges seem to be a little more forgiving as to the small adjustments, and variance of tracking force.
This is probably partly due to the design of MM Cartridges.
Moving Coil Cartridges I understand are different.
Let's take a brand new Benz Mc Cartridge, let's say a Glider. Now, I'm guessing here a bit, but let's say the factory recommends a VTF range of 1.8g-2.2g. One should not automatically assume fresh from its case, that an even 2.0g is going to be an optimal setting. At least it might not be at first.
Due to lack of any break in of suspension components at this point, one might note sibilance, and mistracking at lighter settings. But that will change over time with break in.
That MC Cartridges usually aren't a "Ron Popeil" sort of affair, where you "set it and forget it" if you want to achieve the best sound such a cartridge can offer.
After a period of break in, then one should start to begin experimenting with lighter settings, provided sound appeared to prevoiusly be clean at that point in time.
The best that any MC Cartridge will sound, is at the lightest VTF it can track, without any distortion in sound being noted. This will be where the cartridge will display its best air, detail. And many of these Cartridges will sound audibly different with a change as little as .1g.
No two cartridges will behave the same. So, what may work for a Benz Glider I own, may not work for the next person. Age, and sample to sample differences will influence this.
Keep in mind, that all tests should be done with real music, not some torture tracks on some test record. To adjust any cartridge to such will suck the best sound from any cartridge. Torture tracks are just that, and they were designed to make all cartridges mistrack. The goal is not to get through all the tracks with no mistracking. The goal is to note when mistracking occurs, and if mistracking and distortion are equal in both channels.
Lloyd Walker suggests one good method, where you set light, and increase till tracking errors vanish. The other, is the exact opposite approach, to set slightly heavy, and back off VTF just until mistracking begins to occur, Then, in this instance, you ever so slighty increase VTF until these anomalies disappear.
And 3 years down the road, adjustments may again have to be made. In other words, what had worked at the 100 hour mark with the Glider, may again not be optimal 1000 hours later, that again, adjustments (usually lighter VTF) can be again made.
Stylus Force Gauges-Scales that are accurate are a big help, but it is the ear which is the optimum criterion always. Trust your ears. Mark