MMC2 is a great cartridge when properly working. Dare I say it is superior to the AT440MLA. Since you already own the MMC2, the notion that you can renew it for the cost of a new ruby cantilever and LC stylus at SoundSmith ($250 for the basic version) should be tempting.
But it's your cartridge, your money, your choice.
But it's your cartridge, your money, your choice.