Cartridge for Spacedeck w/spacearm

Considering Shelter 501II or Dynavector 20X-
L. What are the characteristic differences between these cartridges? Should I worry about the Shelter on the unipivot Spacearm? What are the recommended cartridge loading values of these? I am using a Sonic Frontiers SFP-1 phono stage.
Another suggestion (that comes from a friend of mine who has exactly the same TT & arm): Benz Micro L2. I believe that he is having very good success with this combination after trying a number of cartridges incl. the 501 Mk2. The L2 has a very unhyped presentation & an excellent midrange.

The L2 has a (static) compliance of 16um/mN so it should perform well w/ the Spacearm unipivot. The only thing is price - it's more than the 501. However, it's deemed as the best midpriced MC by many & even by Art Salvatore!

Bombaywalla is speaking of me. This is the 2nd L2 I have owned after foolishly selling the first one. I think it is a wonderful match with the Spacearm. Very dynamic and detailed but with a natural midrange presentation. I did prefer it to the Shelter, but I must admit to using the 501 with a Bluenote arm which I don't believe did it justice. I later sold the cartridge and arm and am back to the Benz now. It would have been nice to hear the Spacearm/501 combo, but I have no complaints at all about my current rig.