Be honest about how far you got into the course and your participation
Brag or Cry about the Results you experienced from implementing the information
Do NOT promote your affiliated class. If you do review that class, disclose that you are an affiliate. If it's great, keep advertising, and people will find you.
Finally, Close by adding - Yes, it was totally worth it, I learned a lot. OR No, it wasn't helpful to my [insert your niche here] business.
Thank you, honest reviews help us all level up. This is not Reddit. :D
If you are a course creator and see yourself reviewed here, remember that this isn't intended to harm your business. All feedback helps to level up not just your clients but the business models overall. Quality over quantity wins every time.