I am aware that it might not be popular on this site as the most of you came here because you think LN is ground-breaking technology, but personally, I think it is sometimes worth to look on thing carefully and also consider its weak points. I found an interesting video on YT. The author is presenting the basics of LN paying attention to its limitation. 
What turned my attention the most was the routing issue. It seems that the construction of the channels and the dynamic nature of their capacity will not allow doing efficient mapping and consequently the routing also will be ineffective and expensive. I don't know if this issue was already addressed and mitigated. I would appreciate your comments on this topic.