I can't speak to the Theta but I can tell you that I went to 2 Aural Symphonics Optimism v2 cables between a 270SE and 27. The clock signal cable was a real improvement. The music signal, IMO, has become extremely clean and analytical. I would call it incisive, not harsh just extremely detailed. For my taste, maybe a little too detailed. I am considering a new cable (XLR) with a touch more warmth. The problem is that there are so many digital cables available that it's mind boggling. JMO here but if I were you I would stick to XLR but maybe try a few others rather than pay to upgrade the Theta. You could purchase a great XLR cable for the cost of a Optimism v2 and the Theta upgrade.