Do high dollar mono blocks truly improve the Sound Quality over the mid tier amps

I upgraded my PS Audio M700 monos to the M1200s. Wider sound stage with more air. Nice improvement.

@davetheoilguy Thanks for talking about the question I asked and not talking about room acoustics which I did not ask about.  As I said in the OP I love the sound of the Delta amps.  I actually moved from their older model the CT-M600.  When I inserted the Delta's I had an immediate and significant positive improvement in SQ.  That's why I have wondered if there are further improvements to be had. Unfortunately, no one in this thread has responded to my question directly based on direct personal experience with an upgrade.

In a word, no. More expensive amps are often because they use more "interesting" case designs or more colorful shiny bits. 

I looked at the picture of your room and I see a lot of glass there I don't know if it's covered with heavy drapes or blinds but if it isn't you'll be getting a lot of bouncing off the glass which will screw up your sound.