Very interesting. Personally, in my system, with my digital front end, volume is usually between 9-10 o'clock on my preamp. Usually listening volume according to sound meter on my iPhone is about 80 to 85 dB max. My phono gain is around 66 dB. With 0.4 mV cartridge, I usually have volume set to 10-11 o'clock most of the time. With 0.28mV cartridge, volume is more at 12pm or slightly more.
My preamp's sweet spot for SQ seems to be around 10-12 o'clock position and going much beyond 12 o'clock, I think the sound become a bit more aggressive. This is not because the sound becomes unbearable loud but from when I tried lower gain step up on one phono or just reduced the gain on my other phono down.
In my system, I would think that if I have 0.15mV cartridge,I would look at 70+dB of gain from phono.
60dB would be way too low for me, I think.