Indecisive

I spend far too much time thinking about the relative power of various constraints, and honestly, Either/Or pairs are one of the weirdest.

They provide one-fourth of the information about half the cells of Quadruples clues, except that they do give a lot of negative information about seven cells in a row or column, which is more than many other clue types provide.

Rules:
Normal Sudoku rules apply.
Digits in circles appear in one of the two adjacent cells.

Estimated difficulty: 1 out of 5