Howdy Viridian,
I own 2 Shure V-15 Type III Cartridges, and directly from the factory booket that came with this Cartridge, VTF is recommended fro. .75gm to 1.25gm.
Typically, I'd usually set my own at 1.2gm, as at the lighter settings, mine seemed to get quite woolly, and not play at it's best. Tracking seemed to go to hell in a handbasket, at least with my tonearm-table combination I was using at the time. Your mileage may vary slightly, and with a good high quality arm, and Solid table, you may be able to use the factory recommended settings to good effect.
I'd also like to add that these specs were no doubt for the VN35E Stylus, so I don't know of specs were changed for the later, and I understand better MR? (Micro Ridge Version)
If there's any other info you'd like to know about the Type III, just give a holler, as I have the spec booklet here, and can give you any spec for this cartridge.
