Interesting difference of opinions here.. The deck I did my comparisons on is my trusty old beloved Dual 701, Van Damme exit cables, additional Spacemat and a selection of identical cartridge carriers. The M3-D had ballast added to increase intertia and the N21 is supposed to offer better tracking although 'mine' didn't like the recommended 2.5g downforce. Maybe in a Jelco 750 style arm, things may have been different?
The Dual arm was designed around the V15 III which was available in a special version for the Dual carrier and at the time with original cabling, the V15 III sounded sweeter in this deck than any other combination I'd heard, although a strip of card table baize between top of body and the SME headshell did seem to help take the 'glare' away from the SME 'Improved' arms. The V15 T2 I have is a revelation, treble suckout and all, and in the Dual anyway, offers a solidity and 'musicality' that is highly addictive for me, along with flawless tracking. Interestingly, a good Supex 900E, the Koetsu Black when it worked and a mint Ortofon MC30 Super have no issues in this arm, microphony in the structure being totally absorbed in the cartridge body I found.
Apologies if the above choice of bits nullifies my feelings. I'm sure a more massy tonearm would have 'sorted' the M3-D out. It's certainly a very funky sound. By the way, I also have an M55 body with Ed Saunders stylus, which has a well polished diamond. This is another one I once thought horrible, but apart from a slight bass thickness in my motley collection of decks, I've been surprised how nice it still sounds, while not knowing how different this stylus is from the original...
My vintage 'universal' fixed coil cartridges of choice tend to be old ADC's. I'm hugely fond of the later XLM's, ZLM and Phase IV, which is currently mounted and in regular use. I've always found these sweet but never slushy and with a way of transcending the mechanics of vinyl replay. The Sonus models are descended directly from these (Pritchard designs) and I use my Blue sparingly as styli cannot be got as far as I know.
![Image](http://i132.photobucket.com/albums/q8/DSJR_photos/Dual701withSonusBluecropped_zps99b19c88.jpg)
Hanging on in quiet desperation is the English way...The time has gone, The song is over, Thought I'd something more to say...