Cerrot...Those are really tough questions and I don't think any of us can answer them accurately. Changing your digital cable will certainly change the sound, some just different, some different and better, some worse. The Nordost is a very bright, crisp sounding cable so there are many that could bring warmth and heavier bottom. Changing from SB3 to a Transporter will improve things noticeably in my opinion but whether it is the right change, I cannot say. A different Dac is sort of the same answer as the digital cable. They are all very hard to quantify and you probably will not know until you start auditioning pieces in your system. I know it's not the answer you are looking for but it is so hard to gauge.