Most of us have had that experience - go to a show or dealer, listen to an ostentatious 6-figure dollars (or more) huge speaker, and think to ourselves "god this sounds mediocre or even outright BAD; I vastly prefer my own system!"
This IS a good representation of how hard it is to get a large-speaker system right. It can be much harder than with more moderately sized speakers. This IS NOT a good representation of what a truly well crafted mega-budget large system CAN do. The upper limit is much higher, but getting there is the trick. Amp matching is also crucial at this level.
Two of my major "meh" moments were with Focal Utopias a few years ago - Stella III and Grande III. Driven by electronics deep into 6-figures themselves (Soulution). But then I really dug the much cheaper Sopra 3’s in the next room (VAC Statement tube amps)! Maybe Utopias are just the wrong speaker for me, or maybe I just haven’t heard them yet in the right system. Another time, much longer ago (15 years), I had a "meh" experience with very large Wilsons (Maxx?). I sort of remember enjoying them more than I did the Utopias, but still not nearly enough to justify their expense. In another room at that same event, there were huge McIntosh line arrays which I though sounded VERY good (of course driven by Mc amplification), and at least made a good run at justifying their cost!