Why use a super accurate cartridge protractor

Thanks to those who've replied so far, it's been interesting to hear the different approaches and perspectives. Like Stanwal,I think the difficulty of setting dead on correct pivot/spindle distance is something that could use more attention in devising set up tools. I still remain unpersuaded as to obtaining superior results with a Mint vs. less precise methods IF one still has to "make the final adjustments by ear." (Assuming one has properly set up spindle/pivot distance.) In the cartridge setup instructions with the Vacuum State Guru protractor, Allen Wright says that after checking many cartridge alignments with final adjustment tunings done by ear, there is a consistent trend of finding settings about 1.27mm behind traditional Cotter points on an alignment arc. After spending part of last Sunday setting up an Ortofon Kontrapunkt H with a super fineline stylus, I ended up very close to those points myself.

John Gordon, thanks for your take on it all. Perhaps Vacuum State's unfortunate title for their protractor is a result of "English as a second language." They aren't selling anything, it's a free download they offer on their website. Goatwuss' point regarding "simple geometry" is of course true. Perhaps what is really meant by "ear tuning" is that one finds through fiddling around with their alignment that they prefer the distortion distribution of Lofrgren B points vs. A, as John said.

Moonglum, you're so right. Learning to tighten down the cartridge screws with one hand while exerting just the right amount of counteracting torque on the cartridge with the other hand as things snug up can be exasperating to say the least. Understandably, one may become reluctant to change cartridges if using nylon washers.