Hi Grace,
I think this topic is hotly debated among those who are interested in pedagogy. On one hand you have students who are struggling to keep up, in the other, you have students who need more challenges to keep them motivated.
I think it is great that you have openly discussed both sides equally well. I myself, if I had the power, would encourage all those who are seeking education as their vocation to continuously communicate and challenge their students based on their individual capabilities and abilities.
I was fortunate enough to study under such lecturers and teachers and I could honestly say it has helped me understand subjects far better than my colleagues in other classrooms.