iPods don't have a poor sound quality.
Songs distributed through iTunes had a lower bitrate than what many enthusiasts and producers of music were happy with. This just meant that distributers of music could not make their songs as loud as they wanted to, when they were distributing through iTunes (a lot of bitrate is used up in making songs loud, rather than the musical content) - an example is the Death Magnetic album. This is the reason iPods got the rep of having a bad sound quality, does not apply to broken pods.
Additionally, large songs take a slightly longer time to load, but such constraints are there in many players. Because iPods have no external memory, the battery lasts slightly longer, but not when compared to players that have more robust power sources.
Cowon players drive the headphones better, and offer a longer battery life, although some of their touch players were pretty buggy. I use the D2+ and am happy with it, but I use a friend's nano now and then, and cannot make out any difference in the sound quality.