User Manager/V3 VS V4
From MikroTik Wiki
In RouterOS version 4 User Manager test package was introduced, having major functionality and interface changes:
- Profiles used instead of Credits
- Radius CoA support added, enabling User Manager to send session termination and modification requests to radius clients (HotSpot, PPP, Wireless). In version 3, User Manager was only able to handle requests from radius clients, being unable to terminate or modify a running session