I vote for the Ortofon. Some people prefer the OM20. In my so-so system the Ortofon had a melodious/rhthymic feel to it and the Grado was just "OK". I felt the Ortofon was the best cheap cartridge to just enter audiophile-ness and of course both the cartridges you mentioned can be bettered by spending more money. Let us know how it works out for you and best wishes, Mike.
Grado Prestige Gold or Ortofon OM 30 Super
I have a trusty Systemdek 2x with the stock Profile arm and contemplating whether to get a Grado Gold or an Ortofon OM30. My setup leans towards the warm side of the musical spectrum and I listen almost exclusively to acoustic jazz (ocassionally some fusion): PS Audio 5.6 preamp, PS Audio Delta 100, Esoteric D500 Transport, Assemblage 2.0 DAC, and Mirage OM7 speakers; interconnects are Cardas Quadlink 5c's, Cardas Lightning Digital Cable and Kimber 8tc in double runs for biwire. Any recommendations out there would be appreciated.