I'm new to the Insider Fast group. Using the New Outlook for Mac and love the improvements to conversation grouping for all folders and the addition of the My Day view. Started a list of gaps or features not yet available and there are some key ones IMHO. Look forward to the task and notes module being added.
I concur with others here about the favorites and flagged folders being essential and hope this is added soon. And, what about email folder counts? Unless I'm missing something, they don't exist. More important, however, is the ability to create/manage contact groups, see team calendars, and company Address Book. Also, notice you cannot open downloaded .ics files and actually save the meeting invite to your calendar.
Hoping to see more new features and updates soon, hence the Insider Fast status. 🙂