Is a low output MC superior in sound quality to a high output MC??

"Fixed coil" is a euphemism for what is more commonly known as "Moving Iron".  In MI cartridges a piece of iron is attached to the cantilever, and it is the only moving part. Both the coil and the magnet are stationary, and the iron causes changes in magnetic flux that induce signal voltage in the coil.  Like Peter Lederman says, MI cartridges have lowest moving mass among the three common types of cartridges.

I have not owned an HOMC cartridge in more than 10 years, so I am certainly not up to date on the latest, but before that I owned a Transfiguration Esprit, two Benz Gliders, and at least one Sumiko Blue Point.  None of these sounded as true to life in my system as have any number of LOMC and/or MM/MI type cartridges.  Thus I have come to believe that, as a class, LOMC cartridges are superior to HOMC.  This is not to say that ALL LOMC cartridges are superior to ALL HOMC types.  There may well be a great HOMC out there, somewhere.

Sunny, Many others put $5000 cartridges on $5000 turntables, so I don't know why you would hesitate to try the Otello on the UTurn.  It's a bit odd to me in fact that many people seem more willing to pay thousands for a cartridge than for a turntable.