All we need is a properly written player to be happy with, not particularly rockbox itself. N9 produces a very good sound, especially with some alsamixer tunning. So far there isn't any good player out there. There is a couple of WIP project, though.

QuasarMX seemed the best and the most promising so far.
http://talk.maemo.org/showthread.php?t=81318

I am quite hopeful eventually we will get a proper player feat. all the stuff we need. What QuasarMX foremost needs is more bass!