Superflip plus fourspot

From Wiki

Superflip plus fourspot is the only currently known 3x3x3 position to require 26 moves in the quarter-turn metric. It and the two (distinct modulo symmetry) positions immediately adjacent are the only positions known to require at least 25 moves in the quarter-turn metric. If any other positions require more than 24 moves, they are positions that have no symmetry.

In the half-turn metric it is one of the known distance-20 positions, but each of the 1472 length-20 half-turn-metric solutions has length 28 in the quarter-turn metric, so there is no move sequence for this position that is simultaneously length 20 in the half-turn metric and length 26 in the quarter-turn metric.