Best MM?

Dhcod, cartridges are very competitive; therefore, you are always speaking of the cartridges in a specific price range.

Would you ask someone who is the best girlfriend for you? Of course not, but that's what you are doing in a sense when you ask, "What is the best cartridge"?

While cartridges in the 1K range are very good, there are many trade offs for each brand. You will have to decide which "house sound" is most conducive to the aspects of the music that floats your boat the most. I mentioned the 1K range because that's as high as I am currently going, you might go higher.

For a music lover, nothing is more important than the cartridge; it can put your favorite female vocalist in the room with you, but maybe that's not what you want.

Another cartridge can rock your world, but nix the female vocalist. you see, unless you are in the vicinity of 10K, your cartridge will not do everything.

I have found happiness in the 1K range with a Grado Master; jazz is my thing and I love female vocalists.

Just like you will have to (or you had to) discover which girl was best for you by trial and error, you will have to do the same thing with cartridges. Suggestions from others on this forum is a good starting point, but inevitably you will have to make discoveries for yourself by trial and error; that's less expensive than living with the wrong cartridge for the rest of your life.

Would you ask someone who is the best girlfriend for you?

Try not replace a girlfried with a cartridge, this is the most important. 
And don't tell her how much you're willing to pay for a cartridge if it's more than $200 :)

I found this comprehensive cartridge review by Michael Fremer very useful:

https://www.stereophile.com/taxonomy/term-a/172

Based on the above, and budget, I chose the Clearaudio Maestro V2 Ebony MM cartridge, sound is excellent IMHO. I have no plans to change out this cartridge.

Music is subjective while cartridge specifications and price are objective. It’s needless to compare a $200 cartridge with a 1K cartridge, but cartridges should be compared in the same price range to get anything meaningful out of the comparison.

Anytime someone comes up with a cheap cartridge that’s better than an expensive one, that conversation gets deleted.

In regard to cartridges, I have several points to make; each cartridge, in each price range, in each brand is unique, and there is one that will take you to "Shangri La".

Forums like this are a good starting point, but you will have to experiment for yourself; anyone’s claims that a cartridge is best, means that it is the best for him, or her.

Budget, FYI, is up to $1500. 

I guess it's just going to be trial and error.... starting with either the Audio Note IO3 or the Clearaudio Maestro V2 Ebony.