Othello Vs Checkers -- are there any complexity and skill comparisons?
From AI point of view, or at least from a Search-intensive approach, Othello is harder.
Checkers has been weakly solved at 2007. Othello has not been solved yet.
From the paper Checkers Is Solved:

Search-intensive approaches to AI will play an
increasingly important role in the evolution of the field.
With checkers done, the obvious question is whether
chess is solvable. Checkers has roughly the square root of the number of positions in chess (somewhere in the 10^40 - 10^50 range). Given the effort required to solve checkers,
chess will remain unsolved for a long time, barring the
invention of new technology. The disk-flipping game of
Othello is the next popular game that is likely to be solved,
but it will require considerably more resources than were
needed to solve checkers.