For me, I feel Saul has better technical ability, yes he hasnt shown it so far but its there, his confidence is just so shot. Bakayoko to me, not so much. I remember him playing 45 mins i think against Spurs in a friendly and it was brutal.
Bakayoko had a full season, so I'll wait till the end of season to rate Saul too. Good thing is if Saul is a total bust, we can return him.