Frankly, I would not waste any real money on a Transport, only on a CD player that you use the analog outs for DSD. I do think you should improve the transport jitter though, by adding a reclocker to the digital cable as well as a better digital cable. The soundstage/imaging problems you are describing are likely jitter related. To get the jitter levels you can get from a $599 Synchro-Mesh reclocker and a $499 Reference BNC cable (20psec), you would need to spend at least $20K on a new Transport IME. You can make the reclocker even better by upgrading the power supply. I would do this first before you consider a new DAC. 30-day money-back, less shipping.
As for the DAC, I can highly recommend changing to a DAC with balanced outputs if you don’t have that already. This will usually give you a lower noise floor and better soundstage as well.
First, just try the new cable and reclocker and see if this does not satisfy you. It also provides galvanic isolation, eliminating a ground-loop that you have now.
BTW, if you also have a home theater with SS processor, I can highly recommend the iFi SPDIF Purifier for $149 driving my Standard BNC S/PDIF cable to reduce jitter for Dolby Digital and DTS.
Steve N.
Empirical Audio