I have been learning how to use this product for several days. I am not the owner of this account but the owner's technology director, so I am using it to share what I've found during my usage of it. I appreciate the amount of work put into this system, and most of the features seem to work good, but there are some issues I've encountered along the way.
1. No restrictions or control over the messaging feature (at least from what I could tell). Once you invite someone onto one of your Hubs, they could theoretically start spam messaging anyone on that person's hub with messages and create group chats willy-nilly.
2. Extremely slow server. Everything runs very slow and has considerable lag, especially when it comes to loading pages. It is slow even to run on a computer with a fast fiber optic internet plan, but is worse on phones and slow networks.
3. When you try to delete a calendar item that you didn't create, it won't let you delete it. But you can edit it, and after you edit it you can delete it. Works but is not intuitive at all. (This may have been fixed already, but I don't remember: I encountered this last week).
4. Excessive number of emails sent when delivering invites. I sent an invite for a Hub to a test account and received four separate emails with the same message. Two of them had the name of the person who had invited them, two of them did not. Not a critical issue but a bizarre one for sure.