Interesting point regarding the “direction of focus” I agree that the Leica/Zeiss and Olympus direction is intuitive. And to fuel the flame, consider the placing of the lens diaphragm control on Zuiko lenses to be perfect too. As well as in its use ie closing down being a clockwise rotation. But this is a personal preference.
Coming back to the original question I would opt for Olympus OM as an all round well balanced system, although the versatility of the Pentax ‘K’ mount has considerable advantages.