Google My Maps is a great tool for teachers and learners. Teachers can use it as an interactive platform to present lesson materials. Learners can use Google My Maps to document what they have learned.
This is a good overview of Google Maps Tom. I note your issue with sharing ‘a copy’ of a map. I wonder if this relates in part to the fact that MyMaps is not a part of the core Education offering? One workaround that I have used in the past is have teachers provide a copy of a KMZ and then get students to load this. Although it involves a few more steps, it at least gets there in the end.