Not sure if the kc06 is the same as the A in regards to soundstage and imagining, but my "wall of sound" impression was/is to explain the overall feeling, especially compared to the FX850.
The Mids are slightly recessed on the KC06A. The sound like a small step back from the rest. Since the whole spectrum is very in your face, the slightly pulled back Mids give a false sense of stage, at least in my opinion.
It becomes undeniably apparent for me in live recordings.
I have a live recording of Lisa Hannigan at The Troubadour in Hollywood. I was at the show. When I listen on other setups from cans, to earphones, to speakers, it makes me feel like I'm there again.
When I listen on the KC06A it sounds like I'm 1 foot in front of the stage, all the band members are right next to the Mic, and the bar with people drinking is 2 feet behind me. Everything sounds lively, but some of the life in her vocals is just lost.
Some live Zeppelin confirmed it for me.
That was a huge factor for me. That recording really brought to life the few flaws that are just not within the boundaries of acceptable for my general listening preferences.