Current injection (amplification) phono stages

I think I started a thread on this type of phono stage some time ago, maybe not here.  After reading Fremer's review of the BMC MCCI, I developed a strong curiosity to try it out.  I think Fremer was trying to underplay the fact that he actually found it to outperform his standard piece, in some ways.  Have you heard one?  "Current injection" is a cute term; I hadn't heard that one before.  Aqvox is much liked by its owners, and cost is very reasonable.

I am currently playing with the Avari - it's awesome.  I would like to get the Avari, but am worried about it's resale value - nobody has heard of them, they don't respond to emails, have 0 social media presence, so if I buy it, it will be my "forever" phono.  It is however much better than my phono (built into the Soulution 520 preamp), and it is  better than the 3x as expensive external Soulution phono (5 series)...

The new Sutherland "Phono Loco" is also a transimpedance phono stage that should be on the short list.  It is superior design and offers unbelievable performance - definitely worth checking out.

As I recall, after researching this type of phono stage, I came to the conclusion that there is an internal theoretical contradiction. That is, for ideal transfer of current you would want zero impedance at the input of the phono stage. But in fact you have to have at least some impedance in the form of a resistance between the grid and the ground or cathode of a tube or between the gate and the ground or drain (or collector) of a transistor, or else those devices don’t work. So in operation, they all present at least a two or three ohm parallel resistance at the input. The proof of the pudding would be in the listening.

jwp, Why do you say that the Sutherland is “superior”. What is it superior to, and what makes it superior?