The rating is based on degree of support, not efficiency. Polling is widely supported. Subscription is not. Will take this phrase " so consider the ratings in the table in parallel with the decision tree found  following the table ." and make it bold.  Will also append "i.e. A 'High/High' rating does not imply that the solution will be the best option for a particular use-case.  However, if after evaluating the options based on the decision tree, there are multiple possible options, their respective adoption and re-usability ratings may help to choose between them."