While I do like the new admin center, but why should I really use this over just RDP'ing into the server. You have some of the modules (Active Directory, DHCP, and DNS) in preview mode, but they really aren't useable.
The other thing is in most RDP connection manager we can have multiple tabs open, but in Windows Admin Center you can only have one connection to a server, cluster, etc. Don't have the ability to click and tell it to open in a new tab.
Not sure if this is really a place for it, but there doesn't seem to be a Group Policy module and maybe not something that can be put into Windows Admin Center.