+1 for putting the first PSX-R on the DAC-XP then the next on the CD transport, IF you have one, or have gotten hold of one half price, that is. Otherwise I'd save the cash towards new power amps.
I can't see a so-say cleaner more stable power source doing much to the 1's and 0's coming out of the CD transport, and in my experience (PSX-Rs on the CD-XT, the Pre-X, and the twin X-powers in my system), I can't honestly say I noticed much difference, except, perhaps in the dynamics of the power amps, but there you go. A certain popular internet auction site, ahem, seems to be a rich source of PSX-Rs at about half price, so I don't think I'm the only one wondering about the merits of PSX-Rs.
If / when I get around to replacing my Cyrus system here in the US, I'll probably go for Mono-X200s or X300s, and probably only put PSX-Rs on the other components if the notoriously "spikey" mains here in Houston demands them.