You can call it a transport, but in reality the FLAC or WAVE files are treated no different than regular data files. There's no jitter generated.
The biggest advantage, for me, is placing the computer away from the listening room. Any whining or clinking noises from Hard Drives, CD transports and power supplies are eliminated.
And yes, the SB3 should be Stereophile's product of the year. It's a revolutionary product!