MOD playback is now a minor part of the FMOD functionality. It's still important, but it is now just a small part of a very large feature set. Stream support (MP3, OGG, WMA, etc) is now a large part of the functionality that is used. For a DLL that sits around 150-160KB, it is a very powerful and very efficient sound and music playback library. FMOD4 (in public beta now) is even more powerful, but just as efficient. Quality of playback is very high as well.