Pretty amazing. I understand regarding the YG. I have had many other speakers, including some like Magico and Wilson which basically "steals the shows" by reviewers and hence people often follow the reviewer crowd, while NOLAs get such little press or audition time. I look at it as other people's losses.
I can't say what you will lose going to the CGRG from your NOLA GR6G, maybe Carl can chime in, BUT I can tell you my CGR IS the best speaker I have ever owned or heard. Once a person hears the magic of Carl's speakers "PROPERLY" set up it is hard to go back to others. I am driving mine with ARC REF10 Pre, ARC's new GS150 (one of my favorite components of all time), MSB Diamond Plus with Valhalla II. I was using the REF75 with amazing results and Carl's amp of choice but I am not sure if he has heard the GS150 as yet. It is just an amazing setup.
I look at Carl's speaker as craftsmanship (sound not necessarily looks) similar to a fine watch. He tunes his speakers like few others do with abilities few other have.
It is difficult to explain the sound of the Grand Reference 6 Gold so I will share a couple of my Grand Reference experiences.
There was the time when we first showed the system at CES. I was playing the Reference Recording of Fanfare for the Common Man. A reviewer who was at the original recording session came running down the hall because he thought the drums were real.
Another reviewer who lived in LA was using our restroom while I was playing the soundtrack from Jurassic Park. He came running out thinking it was a real earthquake.
Cary Audio was above us and they frequently commented that their floor was flexing up and down.
By the end of that show we had managed to blow off half the leaves of the ficus trees we were using for room treatment. They sat on the floor when the rental florist came to pick them up.
At the Munich Show in 2012, a reviewer complained that the bass could be heard two floors below--and yet the bass balance in our demo room was not exaggerated. The 4 towers were being driven by 1 pair of 80 watt 300B mono blocks.
At this show, we were jammed by wall to wall people all 4 days such that is was often difficult to get a good demo. And this in a 65 sq m room that is more like an airplane hanger than a room.
Many couples took photos of themselves standing in front of the towers--as if they are some kind of landmark. This was a humbling experience for me and my family. I had never seen anything like this.
To sum up I would say the Grand Reference is the least boring loudspeaker I have ever run into and provides a different level of experience.