Well, not exactly the MediatorDi model I have, but I do have a Mediator board sitting in my Amiga 4000 and one in my Amiga 1200...
The Mediator works very well, so do the drivers. But how do you determine if drivers work well anyway?
Graphics speedwise it is quite good, at least compared to a CyberVision64/3D which is one of the graphics board I have tried before.
As for soundcards and playing mp3s, then it will take up a lot of CPU time. A sound card will give you better sound, but there is no integrated mp3 decoder. If you want to play mp3 with little or no CPU usage, then you need a MAS Player or something similar.
