Microsoft is ready to sign Windows 10 Mobile RTM build as soon as early next week and the RTM build could be 10586. However the RTM build coming soon to Windows Insiders.
The Windows 10 Mobile RTM build will not contain any new features, but there is lots of performance improvements. However folks at WMPU has got some screenshots of Windows 10 Mobile build 10586 (RTM Candidate). You can check the screenshots below:
