I like that it has many features, including tasks/inbox management with email alerts for new messages to keep me up to date without having too much clutter in my inbox! It's easy enough if you're familiar wtih Outlook or Gmail but there are some things not intuitively obvious at first glance (like where certain fields go).
The UI can be less than ideal so make sure your team uses this product effectively before purchasing more licenses as they may need training from their IT department since Microsoft doesn't provide support outside of paying customers - which isn't cheap either way unless its something simple such as adding another user account type within Active Directory groups. We have been using GOWorkflow extensively throughout our organization over several years now because we've found ways to use all aspects of Groups + Teams well beyond just employee communication.