I have had the SMMC1 for about a month now and I have listened to digital only for comparison since. It is surprisingly detailed, appears to present an even response top to bottom, and has a pleasantly wide but not overly so soundstage. My only complaint at the moment relates to a slight reduction in soundstage depth as compared to my Cary 308T cdp, and the production of excessive sibilants on some female vocals. However, I am only using the stock phono stage on a MF A3cr pre at the moment, so I wonder if an upgrade there might alleviate these problems. I have been seriously considering either adding an external phono stage or significantly upgrading my preamp to something with a good onboard phono stage.
It looks like you have to completely open the RX2 to change the belt; my replacement has arrived but I have not yet turned the screwdriver. BTW, there is a hidden black recessed knob on the bottom of the RX2 that sets tracking for the MMC2; you should check it. If your MMC2 turns out to be in good shape, I wonder if it fits the acrylic adaptor for the SMMCx series sold by Soundsmith?