I have owned Sony Ericsson T10, Philips 350, Philips 755, Nokia N73(ME), Nokia E61i mobile phones (in the same order) previously. The initial 3 were non music phones, N73 being my first music phone. It sounded OK and always felt short in front of the SE music phones in terms of SQ but it was an overall package. My current E61i also doesn't perform that well in the sound department but I have been living with this phone for so long that I am now used to it. Don't listen to music on it though. I prefer my music system for dedicated music listening.
* I have found that the bundled music player in the Nokia phone is not up to the mark and the third party player LCG Jukebox brings a lot of improvement in the SQ. Try it!! *