All mediaplyers use chips designed to stream, and the NAS function is available only as a consequnce of that. Those chips only come from two companies, Sigma and Realtek, and both design to that rule. The software limitation is...the hardware. It can't run it any faster.
Lan interfaces only come in three flavours,10,100 and 1000. There is a huge gap between 100 and 1000. Devices which where pushing 100 mbps "allocation" limits don't suddently jump to pushing 1000, but have to use 1000 as that's the next step up.