If you want to go into detail, with differences in phono stage gain of a few DB, as in this case, the amount of satisfaction of the user is going to be related to the gain characteristics of the downstream components. How much gain does your line stage add? What is the input sensitivity of your amplifier? The input sensitivity is defined as the signal voltage input necessary to drive the amplifier to full output. And finally it depends upon the efficiency of the speakers, obviously. So that is why answers in the range of 60 to 65DB can all be correct, depending on the downstream components. In this case, you have the opinions given, none of which is really wrong.
Oh yeah, too much phono gain, e.g., 66db in this case, is almost never a problem.