Geez Chazzbo, you take this way too serious. And your recommendation of the EAR 324 is commendable, but with only 54 db of gain, this will probably not be suitable for the Koetsu Jade at 0.25mv but may be fine with the Clearaudio Goldfinger at 0.8mv that Koocho is considering.
As an owner of the Koetsu RWS and Clearaudio Accurate cartridges driving the Aesthetix Io phono stage, the last thing I want is a bunch of extra switches, pots, wires, etc., in the phono stage to change the loading or gain to match my cartridge. After putting in a new cartridge, it takes only 10 minutes to remove the Io's top to set the appropriate gain with the jumpers. And it takes another 10-15 minutes to move the loading jumpers on the back of the unit for the desired result. If I paid this much for these products, why do I want all the extra junk in the signal path? I'll put up with the little bit of effort from time to time rather than sacrifice the performance. If someone sits in their recliner chair, with the remote in their hand, adjusting the gain or loading on a per-song or LP basis, I think they have lost the point to listening to the music.
Concerning the Rhea having quality control issues, I'd like to know where you heard this. Other than a problem with resistors in the earlier Jupiter models and also some bad batches of tubes in the Saturn models, these products have not been troublesome to my knowledge. When such units like the Io, Callisto, Rhea, Janus, etc., have so many tubes, they will certainly require more attention and maintenance. If someone is not willing to deal with this, then solid state products are a better choice.
And speaking of Counterpoint, you do not have to go back to 25 years. The SA11/SA9 were strong 10-15 years ago. And these too were loaded with tubes and thus the potential of reliability issues. If you read about the updates now available to these models made by Michael Elliot, you will see that he offers options for many of the adjustments to be bypassed.
On the issue of removable headshells, arm tubes etc., I suspect that many companies stay with a one-piece construction due to regidity and coupling. Perhaps a qualified mechanical/structural engineer can chime in here. But I would think that there is a higher potential for loss and resonance problems with all these parts "bolted" together.
I do not see the situation as grim as Chazzbo makes it sound to be. Koocho: one of the biggest issues for the higher-end Koetsu and some Clearaudio cartridges is their low output in the ranges of 0.2-0.4 mv. The Aesthetix Io offers 80db gain with no step up transformer. I run my two cartridges at the 74 and 68db settings....I find the 68db matches more closely to the same volume adjustment as my DAC so this is where I keep it. One simply needs to put forth the effort to find ultra-low noise tubes for the Io's input stage. If they simply report that the unit is noisy, and they have not made this effort, they have not heard the true potential of this product. But even then, it is not the most quiet phono stage out there.
When I had the BAT VK-P10 phono stage, I used the step-up transformers and the sound was very good with only a very slight loss in detail vs. no SUT. But without the SUT, the level was just barely acceptable for higher-volume listening. There's a lot of varying opinions and non-sense about the "sonic destruction" done by SUT's. Many of these people say the same about tube-based products so I take their comments with a grain of salt. You have to determine the usage of these for yourself.
Rather than feel pulled in many directions, I suggest you read the forums here and get a good feeling on the pros and cons of the phono stages that are praised by many A'gon members. Then make the effort to borrow a couple of these and try them out in your own system.
John