SDL does have a very good mixer/playback library for many audio formats (including MODs) however, unless it's been fixed since, on Windows (not confirmed on Linux or Mac OS X) there seems to be an issue with playback of audio at 44.1kHz. You'll have to set your audio only as high as 22.05kHz on Windows if you want to use SDL's mixer for playback. This seems to be the biggest drawback to the 1.2.x version of SDL on Windows. I'm not sure about 1.3.x or other platforms as I've not used the mixer on anything other than Win32/SDL 1.2.x, but it has been reported that it works just fine.

Can anyone confirm or update us on this issue?