We'd appreciate the faster transfers, if your CPU can handle them
This is a hardware issue relating to chipset and other matters, so unfortunately, it is easier said than done, as it creates an obstacle for keeping the device cost down. Also keep in mind that the whole promise of the device is to work in the background 24x7 efficiently, as opposed to delivering lots of speed on demand.
Fair enough. Is there a limit on the maximum size of an attached disk?
We are not aware of any, but we have not tested as fully as we'd like. 2TB and below we know have no issues. We have some people using 3TB drives without issues also. We are currently working on confirming 4TB, but not quite done yet.