MC or MM?

All of the Grado cartridges are versions of moving magnet, not moving coil. Moving magnet cartridges have typically higher output and are sensitive to capacitive loading (capacitance of the tonearm cable + the input of the preamplifier), while moving coils typtically have lower output and are sensitive to impedance loading. That is why a moving magnet input has lower gain and fixed impedance (47k ohms) and perhaps a choice of capacitive loading. The moving coil input may have different options on gain and perhaps a choice of impedance loading (e.g., 100 ohms, 1,000 ohms and 47k ohms).

As far as sound is concerned, my preference is for a good moving coil. There is so much more detail, liveliness and sense of "air" on the top end with a good moving coil. There is a reason why there are not many premium-priced moving magnets offered. As for the really costly Grado's, like the statement, I personally do not like them. I can understand why people like their rich, warm and woody sound, but to me, they are too inarticulate, muffled sounding and shut down on top to justify their cost. The cheaper Grados are another matter. I can see why they would be preferred to some of the cheaper moving coils which can be very thin, brittle and overly bright sounding.

Some more info for you FWIW:
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1079557664&read&3&4&

Actually, the Grados are Moving Iron (MI) - a variation on the MM theme. A Moving Iron cartridge uses a fixed coil and fixed magnets. The stylus is attached to a small piece of magnetically permeable metal (such as iron) located in the magnetic circuit between the coil and the magnet, but not to the magnets themselves. When the stylus vibrates so does the permeable metal, which in turn disturbs the magnetic field around the cartridge, which in turn generates a voltage in the coil.

The advantage is that the permeable iron can be much lighter than the magnet, yielding many of the same theoretical advantages of the moving coil.

RE: DOPOGOE
You're not kidding about Grado's nomenclature being confusing.
I called them yesterday to see if they would clear up the descriptions for me and it helped somewhat.
Names like: Statement series Reference & Master,Reference Series, Reference & Master? Elliptical diamond or nude elliptical? High output or low output? Basically they told me that you work your way up their list on their web site to get from their standard to their best. Problem is, eight of their cartridges are listed with two on each line. Unless you know which diamond & output is better you are lost.
Good cartridges, but really confusing part numbering system.
By the way, they told me that the low output is better grade cartridge, do to less wire to travel through and the nude elipitcal diamond is the better of the two. They also told me that I was only about the second one in five years to call up and ask for clarification on their product line.
Maybe since their information email account has been down for a year folks just plain gave up...

So THAT's why my Grado - in a low-mass tonearm or fuggedaboudid - sounds so detailed and dynamic I haven't touched my expensive MCs in months! No more artificial highlighting of the high frequencies and mucking up the timing! No moe mid-bass suckout! Ah, beautiful music instead of those constant plucked strings...where did that instrumental resonance and decay go?