Perfectionist: You raise some valid points here. Jadem6 (JD) and I have had much discussion about these two Aesthetix pieces. We have directly compared them at three different times at our homes. If you have not already read the reviews he wrote here about each of these models, please do so as it will give you much greater insight than what I can do here.
Any time someone asks for opinions about one product vs. another, almost inevitably one product is going to take a little abuse in the final analysis. What I like about this site is the openness of viewpoints rather than the typical magazine review where the reader is left hanging with never getting his own questions answered as to what the writer genuinely heard.
I will try to give you a better perspective here on MY take on the Calypso. First of all the good news: tonal coherency, low-level resolution, frequency-extreme coverage - these are all covered impressively well with the Calypso. Where most tube line stages fall short in the bass, this unit does not. So many tube line stages over-emphasize the mids with sacrifice to the frequency extremes; again not here with the Calpyso. The Calypso has a wonderful natural tone that far supasses the line stages in this price range that I have heard; there is not even one tiny hint of fatigue. AND resolution.... this unit brings on so much more detail and clarity from the music, especially in the trebles. In the context of the BAT 31SE and ARC LS5 II & III that I owned, the Calypso far exceeds these models in these areas with the BAT being very similar in the bass. It is remarkable how nearly identical the Calypso is to the Callisto in these areas. From my extensive auditioning of line stages, my gut feeling is that the Calypso has no peers in these areas in its price point.
And now my personal biases enter the critique. Ever since I heard the ARC SP-8 totally annihilate the great Krells, Klynes and Spectrals of 20+ years ago, it forever changed my perspective on what preamps can do to the musicality of the system. Once you hear an instrument occupy space and render decays in piano, sax and voice, it is tough to give it up. All these years, I have been willing to sacrifice low-level resolution, the utmost in bass control and extension, deal with a higher noise floor, etc., if that was what it took to achieve the 3-dimensionality in the performance that brought on the emotional connection. With each upgrade, the SP-10, LS5, 31SE, Callisto, I have managed to achieve all of the magic in this regard that I had before, but also to build on getting improvements in the areas that were lacking before. No matter how refined those other attributes might be from a product under consideration, if I was to lose any of the "magic" that I had worked so hard to achieve up to that point, that product was not going to work for me. This alone is why I have yet to jump up and down in excitement from any solid-state line stage or preamp. I'm simply a bloom and decays fanatic and I have sacrificed the other areas to get these attributes. But what has totally knocked my socks off (and JD's too) is how incredibly well the Callisto literally does it all.
As JD wrote above, and take his advice seriously, do not listen to the Callisto if it truly is out of your price range. If the Calypso brings on a huge smile to your face when you hear how it surpasses its peers, like JD, you will be a proud owner.
Your issue of fairness is a good one. Of course price comes into it. But that was why I brought the BAT 31SE into the discussion. It is in the Calypso's price range on the used mkt. And for me, it brings on the emotional aspect to the performance much more than the Calypso. But with the 31SE I am also fully aware that subtle details are lost from the music, primarily in the percussion that is rendered beautifully with the Calypso. The BAT is definitely more mushy and grainy on the top. But like the Calypso, the BAT was never fatiguing with overly emphasized mids as was the case for the ARC LS5 and less so, the LS25.
It's really tough to let go of the details in the music. But for me it is more difficult to let go of the dimensionality and space. It's a personal decision. Perhaps other links in the system with complimentary strengths can make the loss in either way "doable".
But trying to correct either of these issues with cables will result in only a lot of frustration. The result would no doubt mess up the tonality and potentially bring on fatigue as you tried to make up for lost extension on the top or make the sound more warm and rich with something like Cardas Golden Cross.
It would benefit you greatly to borrow a Calypso or 31SE for the weekend and hear for yourself how they differ to what you already have. You ultimately may want to keep what you have. Or it would give you some insight to check out the CAT Ultimate, First Sound, or others. To lock yourself into just a couple of models makes it tough to find the model that clicks so well to your own set of biases and system matching.
John