Latest issue of Distrowatch weekly includes a review of Neptune 4.4, written by Jesse Smith, as feature story. Neptune 4.4 is a Debian based GNU/Linux distribution featuring KDE 4 as default desktop environment.
This review remarks that, despite of a simple straight forward look and feel, this distribution offers a solid, useful and easy to use desktop operating system.
The Neptune distribution is a Debian-based project which offers users a friendly, desktop-oriented experience. Neptune uses KDE 4 as the default desktop environment. The latest release of Neptune, version 4.4, includes mostly minor upgrades with an eye toward improving the graphics stack and desktop performance.
Neptune is available in just one edition for the 64-bit x86 architecture. The ISO file we download is 1.8GB in size. When we boot from Neptune's live media a menu appears and asks if we would like to explore Neptune's live desktop environment using English or German as our preferred language. Neptune then boots to the KDE desktop.
See complete review here