I do like the datepicker, but wish they had a panel between the calender month view, and the year navigation that displayed the months of a given year. Date of Birth is a very common use case, and navigation between months would be faster for more than 1-2 forward/backward as an intersticial.

Didn't test for small displays, or the other components.

Aside: I would prefer they used the term Browser Components or HTML Components instead of "web components" as it makes people think of the Web Components standard.