Sol, I use MIT 330 Shotgun, both RCA and Proline (my linestage is rca only right now, when I use it). The Proline is the best bang for the buck, I got this 2 meter pair for $550 used. There might be something out there better for the price, but I've heard many of them, and I doubt there is...I really do...at least with similar systems to mine. MIT has had a few duds, but when they get one right, they're better than all the competition! Guys that don't like MIT, have not heard these latest "High End" series. I also found a terrific deal on a 4 year old 350 Shotgun EVO RCA a couple of months ago, and will try to compare it to every RCA interconnect around that I can, to see how the rest measure up. You wouldn't believe how "not there" THIS cable sounds. Anyway, the 330 Shotgun Proline connects the balanced output of my CD50 to the balanced input of my Krell, and the improvement was astounding (in every way) over even the 330 Shotgun RCA (connecting unbalanced). I don't know if equal credit should go for both the cable and the balanced connection, or if one should get more credit than the other. The Proline does add a "CVT coupler"...but, the CD50 does sum the output of the differential DACs (many balanced players or DACs do NOT do this), so that the advantage of differential operation can be realized from the RCA outputs. As for Krell, I've never met anyone that thought a "Krell-anything" worked as well unbalanced, as balanced, so perhaps that aspect alone accounts for the higher percentage of improvement.....................In any case, the XLR version of an interconnect practically always seems to have slightly different charactersistics from the corresponding RCA version, and usually the XLR version is better...but not always. Just like balanced operation is perhaps usually better, but certainly the circuit topology is a huge factor there (depending on what the designers prioritized).
