Age old discussion I know but MM or MC? Benefits?

Well I pulled the trigger and bought the Nottingham Spacedeck cw Spacearm and a nearly new Shelter 501 mk3 mc cartridge. This is apparently a medium voltage cart at 0.5mv and was reportedly a good match on the arm but obviously in my system we will have to see.
Cant wait.....

Great. Yes, the Shelter is liked by many with Nottinghams. If you have questions regarding the set-up you might want to talk to Larry from Hollywood Sound, he knows Nottinghams and I think the only distributor/dealer in the US. He also likes MC cartridges. You will probably want to use original Nottingham oil that he should have, though you could get it cheaper from the UK dealers. Belt lasts a long time but still you may want a new one. And of course you will need a record mat to replace the stock. Most people prefer Boston Audio graphite mat, but the company is no more so it's difficult to find. I am sure you read the Nottingham threads on Audiogon, see what alternatives are there. Also, as I remember, just about everyone used one of the three isolation platforms under Spacedecks - 2"-3" maple block, Symposium or Neuance (no longer made) but you can start with the platform it comes with. I use 3" maple block with Boston Audio tuneblocks under it.

@inna 
Thank you for the very usefull information.
The previous owner has included in the sale some original oil and a spare belt which is very nice. But the contact for future reference is helpful.
I will likely try it on maple blocks first as I have quite a few different size blocks around the place.

I don't know about the Shelter cartridge, but with my Goldring MM it took me some patience to set the anti-skate right. It was slightly better in one position with some music and slightly better in another with other music, but these were very small steps.  With VTA set by ear I ended up with the arm in parallel but you have very different and heavier cartridge.
Yeah, Larry should be able to assist you in dialing it in if you need it.

Oh yes, it is much better to overfill with the oil than underfill. One bottle is good for five times, I think. It is recommended to change the oil once a year if you play it a lot and every 18 months if you don't. Besides getting small metal particles in it, oil gets consumed, burnt.