I have to agree that it doesn't sound as good as phones I have owned in the past.

Different note... I just learned that the music store is not supported by a 4gig microSD card. I purchased one, transfered all my songs to the card then got a 505 error in the music store. The phone it self supports the card fine but the music store doesn't. This is a problem that Sprint already knows about because I called them and the tech I spoke with already knew this. Just figured I would share this info as I just found it out yesterday!

Im not so sure its a device problem. I play regular MP3s and they sound just fine but any music store file is pretty low quality. Even when you download the file to a PC it still sounds low quality. I also have used the headset that comes with the phone and a BT stereo headset and still same low quality, so who knows maybe its a tech issue on the company side.