I'm not sure what all the crying is about. I've played with it all afternoon, with no probs at all. It's fast, the quality is incredible and I've had no crashes or hangs.
I did notice that some of the content from the news services was a little suspect. Clips from CNN were grainy and had audio clarity problems. These issues seem to stem from the quality level selected when the video clips were digitized, not the playback.
Our network allows most of the video clips to load in 2-5 seconds and the player begins playing the clip before the entire file has been downloaded. The largest Star Wars clip loaded in 28 seconds and played flawlessly.
I'm running a G3/266 with 48 megs ram. I am also running OS 8.6 beta 9.
I have yet to see or hear a Real Audio/Video clip that sounds better than an old AM radio or a TV with rabbit ears/aluminum foil for an antenna.
If Apple can squash some bugs, I think that 4.0 will be a winner.