Cambridge 840C Upsample & Directv

Has anyone taken advantage of the 840C's toslink inputs to upsample a Directv XM /Sirius signal? While I enjoy a number of the XM / Sirius stations, the audio quality is lacking in depth due to a rather compressed signal. I thought I might try the upsampling feature on my Cambridge 840 to see if it helps.
If you have experience taking advantage of this feature with Directv or another source, please share your experiences. Thanx!
Well if you allready have the 840 I don't see why you wouldn't take advantage of the DAC, it is better than your dtv box. You will find that it is more open detailed and has more depth and even more layering with an overall better tone top to bottom. However it will not be as good as cd's. I listen mostly to dtv xm and enjoy it with the 840 DAC
Thanks for the info Chewy. I do already have the Cambridge 840C & it's connected to a BAT VK-300 SE Super Tube Integrated Amp & I am delighted by both. Thru the same system, the Directv box is connected to the BAT via RCA Interconnects, while the Cambridge 840C is connected with Balanced XLR's.
I wasn't sure how much better (if at all) the toslink from the Directv box to the 840C would/might sound.