AKG tout it as the "Flagship" of their Perception line.
I gave it a lot of thought before buying the Solid Tube which to my ear was built just for me. (no mods required)
I liked the Perception sound when I bought one but by the time I had produced one full album with it, I could pick out that high mid range a mile away.
I think what steered me away from the Perception 820 though, was when AKG and someone around here described their Perception line as being "Entry level".
I was looking to move up from that level but in all honesty, what AKG calls Entry Level is well beyond what some manufacturers produce as their top line.