hmen,
I think the value of the MSB Digital Decoder is far more effective as a digital source switcher versus a jitter reducer. Any digital in -> digital out component has receivers (one to input the digital sound, and one to output the digital signal). Anytime you're inputting and outputting digital signals, there's going to be a minimal level of jitter present.
This amount of jitter is not going to be any less (most likely more) than a current generation $300-400 audiophile CD player (versus DVD/CD player).
In fact, given the age of the technology of the Digital Director, you're probably better off with a newer CD player if the concern is where to budget your funds.
Regards,