Few comments from my side:

-Story estimation is not mandatory in Scrum. Estimation techniques are painful for some teams, so if we see this, it's better to go for a no estimation approach.

-Kanban does not have the concept of commitment? You have two: when you commit to do something at the beginning of your flow, and also when you consider something as "Done".

-I like much more Kanban metrics and also I sometimes use CFD, Cycle Time and Lead Time in Scrum Why? They offer a better view about how "we" are. They show a different perspective: from the customer view and it's more realistic.

-I never too much attention to the Scrum metrics: velocity, burndown chart. It gives the teams a fake view that sometimes is not real.

-In my case, the big mistake is always compare Scrum and Kanban, and also another big mistake is when we speaking about Agile start always with Scrum. Agile is much more than this. The importance is to have a company with an enough business agility being capable to adapt to the constantly changing environment in our sectors.

Anyway, thanks for this article!