12 inch arms have less offset, so skating settings less critical--or use none at all (VPI). They produces less distortion throughout the recording, though the difference is small, than shorter arms. Once set for optimum SRA they change less than shorter arms for changing record thickness.
On my 12" arm I use the same mirrored protractor I used on a shorter arm. Modern version costs "the small fortune" of $20.
Your money; your choice.
On my 12" arm I use the same mirrored protractor I used on a shorter arm. Modern version costs "the small fortune" of $20.
Your money; your choice.