We've been using Sprout social for social media publishing prior to becoming a hubspot partner and have found the reports feature within hubspot is lacking in comparison. Can we suggest that you provide an exportable dashboard/document that breaks down impressions, engagements and clicks as a per post format AND as an overall number or percentage for a specified date range. I've found the reportable information limited in detail/not as comprehensive. Because of this we continue to waste money on our Sprout social account simply for the reporting features.
We are currently using Buffer for similar reasons, the per post analytics are much better and easier to see (not to mention Instagram already available...but once HubSpot goes live with Instagram, would be no reason to keep using Buffer if analytics and scheduling were better)