Neptune 4.5.1 ISOs are available for download now and update the system since the Neptune 4.5 release to the state of 3. May 2016. 

The biggest issue fixed in this release is the usb booting from USB 3 ports. Besides that this new maintainance release features KDE SC 4.14.16 as desktop. 

The Plasma 5 version was updated to Plasma 5.6.2 with KDE Frameworks 5.21.