There isn't any option for me to pick!!
I feel that their videos are more oriented towards beginners in cocos2d-x and -js.
So, I had used them for cocos2d-x around >1.5 yrs back and they were really appreciable
I think other tutorials related to cocos2d-x/JS that I've got on internet are also mostly beginners oriented and not intermediate or advanced users!
Only resources I've found useful after SonarSystems tutorials were sample cocosJS game code provided for -JS and these books for -x
1) Learning Cocos2d-x Game Development by @siddharthshekar (for both cocos2d-x v2.x and 3.x)
2) Cocos2d-X by Example Beginner's Guide (for both cocos v2.x and v3.x)
3) Also, Cocos2d-X Game Development Blueprints (but is only v2.x and was released when v3.x was already well adopted)
And in case, anyone is in a mood to create a tutorial for community and need a decent enough game art creator, let me know. I can contribute as these days I am creating some art stuffs for myself so can spare time.