Your mileage will vary, trust your ears and try different value which you like the best.
Cartridge's impedance loading will differ from rest of your front end system as well. Depends on what type/manufacture of phono preamp, what type of the cable and length you use between your turntable to phono, as well as what type of arm you use(arm and the internal wiring). One top of that, your own preference and the musical taste will vary this impedance value as well, no one number is the magic number for all(this goes same for VTA/VTF).
Cartridge's impedance loading will differ from rest of your front end system as well. Depends on what type/manufacture of phono preamp, what type of the cable and length you use between your turntable to phono, as well as what type of arm you use(arm and the internal wiring). One top of that, your own preference and the musical taste will vary this impedance value as well, no one number is the magic number for all(this goes same for VTA/VTF).