What is the preferred cartrige mm or mc and why

I use both MM and MC, like each cartridge - each has strengths and weaknesses. What I have noticed is that of the 3 phono preamps I use, the MC output is quiter - particulary on my new Parasound JC3 Jr - set to MM, it has an audible hiss when close to the speakers, not the case when I use it for my MC cart. YMMV

EDIT: 2 of the preamps I use have XLR output - same experience with XLR and single ended.