Rather than add to this thread - Max width of containers? - where I would cast my vote to combine Section & Container as I think it is difficult to decide which one to use. I would maybe add in a selection button at the top like Simple | Advanced to display extra features.
Anyway, the purpose of this post is to highlight an inconsistency in how items are labeled and ordered between Container and Section.
You can see from the screenshot comparison that the ordering of the sections is not consistent e.g. Background at the top in Container and after Layout in Section. The naming is also inconsistent e.g. Layout in Section and Spacing in Container. Ideally I would think these should be consistent.
Ideally I think all the Core Elements (and probably Sections (in the Left Hand Sidebar) should show a level of consistency?