I now have the Ortofon A90 mounted on my new Bergman Sindre turntable. I have it tracking at 2.3 grams. I am using my H-Cat phono stage with a 100 ohm load. I don't know how much of what I am hearing to attribute purely to the A90, but the sound is breathtaking. I have a wide soundstage, excellent extension at the top and bottom ends, fantastic dynamics, incredible tracking, and probably the greatest realism I have ever heard.
I started at absolute level but have found that the sound is best with the cartridge lower in back, not by much.
I would like to try the London Decca Reference, but it will be a long time before I remove the A90.