I think PL was influenced to get into MI cartridge development and manufacture by his prior experience with top of the line B&O cartridges, like the MMC1 and the MMC20CL. So he first developed the SMMC line of SoundSmith cartridges, which he still sells. The SMMC cartridges are virtually copies of the B&O MMC series. And SS specialized in the repair of B&O cartridges early on. In my opinion, the MMC1 is one of the finest sounding cartridges ever made, so I very much understand why PL chose that path. As to whether the SMMC cartridges are structurally related to the Voice and its successors, which get ever more costly as you move up the line, is something only PL can say. But you could do worse than to go in that direction. As to longevity, none of us will be around forever, so buy what you like and forgeddaboudit. If the cartridges you leave behind are a significant fraction of your estate, you ought not to be dabbling in this area.
Also only in my opinion, HOMC cartridges are the least good sounding of all types of cartridges that I have heard, and I have owned some purportedly very good ones. I’d much sooner own a Grace Ruby, even with the OEM elliptical cantilever, although the SS OCL stylus does take it up a few notches.

