Due to geometry in tooling and the material, the direction of cut makes a big difference on the finish cut.
Old rule of thumb " if the off-cut scrap has a better cut finish than the part, then your cutting the wrong direction"

Here's an example, a mortise compression tool should be ran in a conventional direction for the best part finish, but using say a low helix finisher for the same cut will give the better part finish in a climb direction
Gary