I had an SL1210 GR and have nothing but good things to say about it. I started with an Ortofon Blue MM cartridge ($200), and then an Audio Technica VM540ML MM ($200), but ultimately went with an Audio Technica art9xi MC cartridge ($1,500), which brought the sound to a new level.
Truth be told, I upgraded to the SL1200G, out of curiosity, but other than pride of ownership, and next-level build quality, I can’t say the sound difference was night and day better. Bottom line, the SL1210GR is a classic table and it’s friendly with a lot of headshells/cartridges. I guarantee you’ll be happy with it. Imho, when you're at the quality level of an SL1210GR, the choice of cartridge is a much larger contributor to the sound than the table.