Stringeen, with my Ruby 3, which possesses I believe the same gain, .34mv, I too am using 60db Gain on my Sutherland PhD. This is the highest gain setting on the Stock Gain Boards, but I do have the High Gain Boards, which are 62, 64, 66, 68, and did try these Boards when the Cartridge was brand spanking new.
It truthfully didn't seem like I was overdriving the Sutherland, or getting a too raw, or hot sound with just very minor gain differences, but I myself "may" go back to the drawing board trying these again, as well as trying a different loading, going from 1000K to 47K just for the hell of it?
The only logical conclusion I can come to..... Is that Benz, with thier new iteration of Cartridges perhaps did something that maybe sounds good on paper, (different materials for Cantilever Suspension, and/or the supposed improvement they made holding the Cantilever) but perhaps was a design-performance flaw?
If they did somehow screw up, doubtful they would be notifying customers to return thier Cartridges for exchange, etc.
While my Ruby 3, as you know is right beneath your LP, and sounds OK-pretty decent, IMO it neither knocks my socks off as of yet, which it should for the price, and IMO too, lacks some of the qualities (slam, midrange beauty, and balance) my much cheaper Benz Glider HO possessed.
Seems like this Cartridge does surprise me at times, depending on the recording, and seems a bit more "picky-particular" with recordings than the Glider was.
It seems to be said, that a low output MC perhaps puts a Phono Stage to a more critical test than a high output Cartridge does?
I would assume as well, after 150 hours of play, your Cartridge "should've" bloomed, and broken in by now? Mark