As someone who started doing courses, I never found exactly what I was looking for. I've wasted my money on so many platforms and was about to "settle" and make it work. Then comes HEIGHTS!!! I was a bit skeptical because I've invested and gotten bamboozled, but this is everything I thought I wanted and some stuff I needed that I didn't even realize. It truly is a course-building and membership paradise. I keep finding cool stuff that's probably outlined in the free course but hands-on helps me navigate better. I haven't found a platform that includes challenges, nor have I encountered a platform that allows you to bundle products and they are still counted as 1. There was a lot of thought put into creating this platform and it shows. Every single question I have is answered in record time, and the founder responds too!
While they are integrating Convertkit (hopefully soon) and other email platforms as native, you can still use a webhook. If that's the only issue, think about everything else you're getting. I have friends that I've shown the back-end of the course I'm building and they are probably going to make the switch too.
If you're on the fence, GET IT NOW! Do not hesitate. Do not let the deal expire. You won't regret it.