Mmm, I feel that "accurate" is the key here (at least for mods), I use xmplay cause I want to hear the music as intended by composer, and I don't use DSP or such, maybe only a lil eq on work speakers. (cheap stuff

)
I felt like winamp mod reproduction wasn't that great (very different from trackers), and it was 1st reason, with the starting bloating of wa, for wich I switched to xmplay. And even lossy mp3/ogg/mpc are "more (crystal) clear", if it's understandable what I mean.
In thruth, I feel like Xmplay is about fact, not appearance, that may or not be its weak point (btw, I like it like it how is now). And for pc music listening that's a great app, really.
[n.b.: about quality... we are speaking about a pc based music system, with usually lossy audio files, which will hardly have better quality of a true hi-fi, even if they label it with 32bit/96KHz/HDEF 140dB SNR and so on; true quality is achieved through stuff that cost a lot more of the average mid-end box]