I wrote an article where you can read that a mid-drive motor hardly outperforms a hub motor.
Hub motor simulation
www.avdweb.nl
In practice there is no significant difference in performance. You can clearly experience this yourself during test drives with both kind of motors, I did this myself too. Because I wanted to know the cause, I researched this subject extensively. The conclusion is that the advantage of mid-drive motors is only noticeable in extreme situations, on steep slopes while the cyclist pedals only a little or not.
I would like to know how others think about this.