That will depend on your love for the truth. The Siemens CCa(earlier than 1968)will allow whatever is fed it to pass with less added or subtracted(more transparently) than anything else out there. That is it's intrinsic value to me. Everyone doesn't appreciate that virtue. Some want their tubes to sound. By that I mean add something that they find attractive, ie: "warmth", "tubiness", microphonics, etc. Like interconnects and cables, some use tubes as tone controls to please the ubiquitous aural palate. As sound tech(over 30yrs now), I get to listen to an awful lot of live(unplugged and amplified music), in a lot of different venues. Whenever I find something in my system that I don't find when listening live: I target that for correction. Then to: I've found a number of things lacking(comparing the system to live). The CCa's simply brought more dynamics, sound stage, focus, liquidity and extension to the table than anything else I tried(Tele's, Mullards, etc.)as far as the 6922 family in past ARC pre-amps, DACs and my present CDP. I've got six in my VK-D5 and have not rued the $$ spend on them for an instant. I figure what I'm willing to spend on my RP's, W's, CCa's and whatever else brings me closer to the sound of live music(and all it's nuances) in my home, will be directly proportionate to my love of that sound. In the past month I spent $700.00 on a power supply upgrade to my pre-amp(greatly enhancing the system's dynamic range), and $80.00 on a pair of Hi-Fi Tuning fuses for the AC in on my Cary Monoblocks(actually made vocals more "organic" for one thing). I knew what I'd gain from the the power supply, but the fuses were a trial. I'll be ordering more fuses for my tube voltage and VK-D5 AC circuits this week. That's just my way of pursuing my musical pleasure. As long as you're enjoying your way.....Kewl! That's what it's all about!