I wasn't keeping exact track (I suppose I could go look up arrival and depature times), but counting on my fingers gives me about 14 hours. Could be as low as 13, I suppose, because I had the unit shut off during takeoffs and landings, and the regular on-off-on-off could have hurt my numbers. But then, I also listened to it while waiting around the airport, so it probably evens out. Either way, I found it satisfactory, and knowing not to expect more than 15 made the loss of music during my last leg not unexpected.

I assume you're referring to that post about Vorbis and FLAC having poorer battery life than MP3? I wonder why that is. FLAC I can understand; larger files mean having to spin up the HD more, but I didn't care because I only have a few dozen FLAC files. But theKompany's music player for the Sharp Zaurus gets better battery life, not worse, when playing Vorbis over MP3, due to lower CPU usage. I wonder why the Karma does poorer.