3 days course - how effective are they?

Hello everyone!

I got selected for a 3 day course and it means that I would be spending 30 hours of meditation. How effective is that for someone who does meditation regularly? Is this course curated for those not practicing regularly? Are the discourses same? And the technique same or there is some changes like going deep into the technique?

I am super thrilled and hope to give my best effort. Thanks everyone for your kind words and encouragement in advance.