What is the preferred cartrige mm or mc and why

MC because it sounds much better done right.I had MM 50 years ago then it was great but sadly its heyday is over.

Dear @atmasphere : """  the loading is there for the benefit of the phono section, which is unstable *if* the loading is a requirement. Other, stable, phono sections with the same cartridge won't need the loading to sound right.... """

Things are that some people read and read and read what you posted about ( I posted too. ) and never learn and follow speaking of SUTs with loading options for the cartridges. I have to say that some  are at the " stupidity border ".

Only a few phonolinepreamps handles the LOMC right.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

I have 2 Shure V15 RS with a variety of Styli including a SAS. I also have an AT 14Sa. I have 3 MCs, a Denon DL-301 II, a very low mileage Dynavector 10x3, and a new Hana SL. Nothing very extravagant. The Shure is as close to perfect on a Linn LXV through a Nakamichi Receiver 2 as I'll ever get.

However on my Alexandria with a Sumiko MMT through a Musical Surroundings Phonomena II, I like the MCs better. I've been tempted to try a Grace F-9; but I fear that the supply of good styli will dry up. I don't see the wisdom of MIs without replaceable styli. What would be some good options in current production that would perform as good or better than the F-9? My MMT can only handle 4 - 8 grams.

2channel8, In this day and age, there is almost no such thing as a non-replaceable stylus.  Such companies as SoundSmith, Expert Stylus, at least two others in the US and one other in Europe, can replace styli on any type cartridge you care to name.  (Well, there may be a few exceptions.)  In some cases, a totally worn out or damaged suspension cannot be repaired, but otherwise, fear of stylus wear is not a reason to avoid this or that vintage cartridge.  I have had the stylus/cantilever of my Grace Ruby replaced by SS with one of their OCL styli on a ruby/sapphire cantilever, a la the original, and the sound is improved.  (I can say this because I also have an original unrestored Grace Ruby with its original elliptical stylus, and I have auditioned them side by side.)  Similarly, I own an Ortofon MC2000 that was repaired in Europe before I bought it.  I am also sure that SS can work on any MI type cartridge; they manufacture and sell excellent new MI cartridges.

The only issue that could arise, if you are a stickler for originality, is where the original stylus has a very exotic shape that is no longer available.  This might be the case for certain Ortofons, Stantons, and some others.  Actually Expert Stylus in England has some of these styli available.  Otherwise, you'd have to "make do" with a modern equivalent.

My experience with Shure V15s dates back several decades, but I found them to be totally underwhelming back then.  I would have guessed that the Hana SL might be your favorite among the MCs you named. By all means, do buy a used F9 or Ruby and have Peter L at SS replace the stylus; you'll be happy, and the Shure will gather dust.

As usual, @lewm , you make a good point. The cost of a ATN150MLX or Goldring D42 are not much less than Peter's services. But the Garrott Brothers P77i is only $270.

All-in-all the F-9 may be the better deal.