My vote is for the RH10. I own both, but to me(and yes opinions vary), the RH10 sounds better. The display is heaps better as well. MP3 playback, I could care less about. People often say the RH10 is bulkier, though I don't see that. The RH10 is a little heavier, but the NH900 is thicker. The RH10 does give up a little... very little on width/height. Dropping the line out on the RH10 was a mistake, but then... I can only think of two occasions that I've ever used the line out option on my other MD players. Guess is depends on what you are gonna do with it. The RH10 brought me back to MD land after the NH900 sent me to iPod hell.