In fact, which course is good, I don't think it can be arbitrarily determined. The key is to choose the one that suits you. I listened to both classes. Let me briefly talk about my feelings.

Chalk course is more systematic and the class hours are longer. Teachers will brush a lot of questions in the course, which is more conducive to laying the foundation.

The course is simpler and more skillful, and it is more practical to solve problems when doing problems.

Generally speaking, I suggest learning chalk and taking sapphire lessons for a long time, and taking sapphire lessons for a short time.