Transferring files to the MyCloud Duo takes place at just under 15MB/s. We were able to transfer DVD size files easily and without issue but...
Transferring any Blu-Ray ISO to the MyCloud Duo resulted in the NAS dropping off the network. It didn't matter what Blu-Ray ISO we tried or from what source.
To check our configuration we swapped cables around and used our house server on the cable / port that the Akitio was on. The result was a nice steady transfer that held a steady 100 to 110MB/s. These are true gigabit Ethernet speeds and the Akitio MyCloud Duo only gives you around 10% of that performance, when it actually works properly.