Perhaps the most frustrating part of developing online learning is the entire design and QA process. In a face-to-face class you can see when things are going wrong and change them. Good teachers come back from each class and reflect on what went wrong and what went well, what problems students have and how to deal with them. For online learning you are supposed to do this before you teach a class!
This is impossible and so QAing a course apart from removing typographical errors is perhaps the most pointless exercise in the process. If you believe in an "active learning" pedagogy then you make an argument that the QA process is there to evaluate the student learning experience - to see what they will see and imagine what they will get from the course. I wish I could do this, that I could get into the minds of all my students and know what will work for all of them. I taught one course face-to-face to 13 students, I had 12 good reports in the student feedback for the first run and one person who simply hated it. For them it was the worst course they had ever done. That was because it did not meet their expectations, it surprised the other 12 but they accepted it.
So how can we possibly do this for online courses?
The only way to have effective QA is to run it, to experience what happens and to be able to correct it on the fly. This is the greatest weakness of VLEs. The amount of effort it takes to change the content means changing aspects mid-course is very difficult and disorientating for the students. Correcting a PowerPoint mid-lecture is so much easier.