Coincidentally I was just reading the reviews of this production this morning.
Obviously I cant pass any sort of judgement without having seen the opera. But I dont understand why people boo at the end of a live performance. Im not the kind of person who believe in credit for trying or any such nonsense when it concerns a professional outfit, and indeed there have been many times where I have declined to stand or applaud, however, these are low degrees of appreciation or indifference rather than an active negative reaction.
I dont feel that such a reaction can be justified within the first seconds after a performance, especially with modern stagings which often rely on metaphor and symbolism, most of which I can only appreciate some time after the performance.
My feeling here is reinforced by your glowing review of the musicians and cast' performances.
I concur by the way that Nezet Seguin is and will become a great conductor. He led the first opera I saw; Janacek's Makropolous Case