I recieved my N800 at christmas and immediately dropped in 2 16gb cards, as it is replacing an archos gmini400 as well as a 770. Listening to music and videos on the supplied nokia headset has been fine with no hiss or anything. However, I was disappointed to find that like the 770 the sound level out of the 800 is a lot lower than the archos. I pipe the sound through an MP3 transmitter, and now have to turn the volume way up on the car radio, and that is after I have ran MP3gain and rasied the gain on all my MP3s.
Other than that one gripe I have found so far that the 800 is a great allround media player.

Gaz