Can't say I have heard anything "chesty" in them. That being said, lean is not a word I would use but they were being driven by 450w amps. A buddy of mine has s5 mkiis and he is convinced that Magicos can't have too much headroom and the more power you give them, the more alive and open they become. If you can give them 1000w, go for it.
Lean might also come from the fact that the soundstage is tall and wide, but to me lacked depth. That could be an unfair comparison because in that same demo I was comparing to Scansonic MB6s and Kaiser Chiaras which have incredibly wide and deep soundstages. I am somewhat soundstage obsessed in terms of wanting an immersive experience. With the S1 MKiis it seemed like music was being presented too me rather than enveloping me which was a stark contract to the Scansonics and Kaisers.
I will say that in terms of placement, I have not played with them in a room myself and when I did hear them, they were a good 7-10 ft off the back wall and 4-5 feet from each sidewall. Placement could be an issue, I can't answer that though.
