So....
Nobody has heard these preamps and or feels comfortable to critique them? I'm very disappointed. So much is debated on this forum but so little has to do with actual hifi gear.
If people had actually heard gear, they would have made their choices easily and debated less.
Also, like many, I have heard all but not in the same system, or not compared them enough to know the attributes of some like the CJ. That qualifies me to debate since I don't have an informed opinion.
So all experiences will be irrelevant to your cause. But another point... Even if one had compared, it would still be irrelevant... Why?
Recently I found that Dartzeel, in the analog chain, did much better direct to the Alieno than via the Nat magnetostat (which worked very well for some stand some phonos). So why would you have Dartzeel in your shortlist, when you have the CH phono, and not the CH pre? A fair compare would only be Dartzeel vs the CH phono plus pre.
I think the AR ref 10 is fantastic, but for me personally, it does not work with 242 valves in the Lampi... Works great with the special 45s. So should I choose to maximize my digital chain, I will choose a pre that works well with my 242, like Aries cerat, while for a non Lampi user I might recommend the AR ref 10.
So, if you are trying to maximize your digital chain, you would be better off following the advice of a vivaldi user, since you own one, like microstrip. But I suspect you are looking to maximize your analog chain, so you will have to choose one that matches your cart, phono, well. I remember one of Tang's posts from last year, from his previous demo of CH, where he said the CH phono performs better with the CH pre. Gian will probably tell you the same.
I don't think you can maximize your digital and analog together with one pre, unless you get lucky. Getting the gain, impedance match, voltage drive, whatever it is, to match, takes systems to new levels of jump and drive with a drop in noise floor. This can be done only by trial and error. From a shortlist perspective, CH, AR ref 10, CJ, are all great. Also Koda