66R and 5.5 cycles per equality check on average.

First unification identifies the first input cardinal, dispersion creates the complement and the second unification triggers if and only if the two input cardinals are equal.

Technically the first unification only need to be used to identify one input, but the 4-by-4 salt brick can be reused as the input of the second unification and it is simpler to reuse everything.

Some parts may look like they can be sped up but it doesn't affect the cycles count since arm 6 blocks the output sequence.