Well just to follow up on what I thought here is a quote from one of the many sites that refer to moving coil carts moving less mass than moving coils. the addy of this site is http://www.phonophono.de/english/html/tonabnehmer.html

Quote: "MM cartridges: Moving magnet cartridges have a magnet situated on the carrier pipe of the tracking diamond, moving correspondingly to the modulation of the record grooves. The coils are permanently fixed to the casing of the cartridge. They can be constructed in large shape and generate a pretty high output voltage (approx 2mV to 5mV at 47kOhms), which can be further processed without trouble. What is disadvantageous is that the magnet is heavier compared with the light coils of MC cartridges. That's why (at least theoretically) the stylus can't follow the deflections of the record groove so easily."

And he continues for MC carts as follows:

"Moving coil cartridges have the coil fixed to the carrier of the tracking stylus. The magnet is firmly installed to the casing of the cartridge. What is advantageous is the low weight of the coil, which has to be moved by the stylus. The coil must, however, for weight reasons, do with few coils, which results in a very low output voltage (0.1mV to 0.5mV at 30 ohms to 500 ohms). Therefore MC cartridges require special preamplifiers or step-up transformers in order to achieve output voltages like those of MM cartridges."

So whilst we have agreement that there is a difference in which moves the more mass we seem to have disagreement as to which is actually moving the more??

Yet another item I thought I had nailed drifts into confusion.....