What's most discouraging about your odyssey is that you have made such a Herculean effort to evaluate phono stages (and to write up your results, thanks) and yet you have relatively little to show for it in terms of useful information. For me, this is in part because you did not audition some well known product which could be used as a reference by which the rest of us might get a better idea regarding what you heard. Reference phono stages might include one or another made by Ayre, Aesthetix, Einstein, Simm, Pass, PS Audio, etc. But I realize that these are all made in the US and may not be so readily available in your country. I am surprised the Nagra failed so miserably. Were you using a SUT or does the Nagra have sufficient gain for a LOMC cartridge? If you were using a SUT, that introduces all sorts of additional variables that could influence the outcome. The EAR 834P could certainly be said to be a reference product; too bad you could not have gotten around the problem with the cartridge. But
834P definitely needs a SUT with a LOMC. If you are in the 4000 Euro price range, I would think you have many excellent alternatives. If you prefer SS, then you might consider the Pass products, but there are many tried and true alternatives.