I bought a SMMC4 from Soundsmith, and compared to my old MMC4, that came with my BG 5000, it is a lot better, tested both on BG 2404 as well and same result, if your vinyl records are in new condition you may hear a difference from SMMC4 to SMMC2, but if not, I dont think so.
I have had 3 cartridged here, 1 MMC2, 2 MMC4, only the before mensioned MMC4 survived, the MMC2, came with a BG 6500 that was stored for some 10 years, after playing 2 LPs the needle came of, the other MMC4 was playing OK for 2 years, then it lost the needle as well. So buying a used one, for me, is not an option.
If you are in EU try Axel in Germany.
Beosound 3000, BL 4000, BL 8000, BG 2404,BG 5000, BG CD50, Beocord 5000, BM 901, BM 2400, BM 4000, BV S45, BV 3702. There is nothing we cannot do, but a lot of things we don't want to do!!