The RadLight 4 Pro interface is easy to navigate (especially the "Oldskool" skin, which mimics Windows Media Player) - it doesn't overwhelm you with options as KM Player does - and the player handles basic playback chores and file types nicely.
RadLight 4 Pro plays OGG, APE, WMA, and MP3 files with its own internal CODECs, but it doesn't handle FLAC. It plays 16- and 32-bit wave files but not 24-bit (a common DAW format) types.
However, the biggest disappointment is that the program doesn't seem to support DirectShow filters. We have Xvid, Quicktime Light, and Real Alternative installed and RadLight still won't play RM, MOV or Xvid supported files. That said, the player did a nice job with subtitles in the MPEG files it did play.
Ultimately, although we like its interface and layout, RadLight 4 Pro lacks the versatile codec support we consider essential. There's an ad-supported Pro version available which adds more convenience features - or you can shell out £34 and skip the ads.