Skimming through other’s input I think there is another aspect that hasn’t been touched upon and that is the source recording quality. I’ve got a BAT VK-600 heavy duty solid state amp coupled with the BAT VK-5i tube amp with my Apogee ribbon speakers and I’ve found that more often than not recordings have excellent left to right, but truly great imaging that also have deep front to back complex spacing require a top quality recording engineer using the right equipment (particularly analog) and this is much rarer. This is particularly a challenge with rock recording roughly around the 80’s era. Once I hear really excellent dynamic recordings such as, for example, many of Jan Garbarek’s (ECM generally as well), Radiohead - King of Limbs, Trifonic - Emergence, just to name a few, I don’t soon forget them and I find myself returning to them like sirens as the years pass!