@NightShade737:
As Kronos pointed out, the 50MB/Sec values are nothing more than a wet fantasy of the Elbox pr-department. Expect 9-10MB/Sec as a maximum with the Mediator Zorro3 solutions and an accelerator which interfaces well with the CPU-FastSlot. The Zorro3 bus is capable of more, but I have not seen any mediator solutions giving much better numbers than that (feel free to correct me if I am wrong).
The daughterboard connector on the motherboard is just a big connector holding the signals for the video-bus, the Zorro3-bus and some various signals for controlling the individual aspects of the Zorro3 slots. The datapath is the same as the one shared amongst all Zorro3 slots so it would be equally fast to interface the Zorro3 bus there as on the daughterboard itself.
The Mediator and Prometheus should be rather equal in performance.
/Patrik