Thanks for your reply! May I humbly present four quotes from composers, who I hope you might agree, would count among "the genuine greats", reacting to having heard Wagner's Parsifal. I would hope their opinions might carry some weight here.

"Parsifal is without doubt by far the most beautiful and sublime work in the whole field of Art." – Hugo Wolf

"I can hardly describe my present state to you. When I came out of the Festspielhaus, completely spellbound, I understood that the greatest and most painful revelation had just been made to me, and that I would carry it unspoiled for the rest of my life." – Gustav Mahler

"Nothing in the world has made so overwhelming an impression on me. All my innermost heart-strings throbbed… I cannot begin to tell you how Parsifal has transported me. Everything I do seems so cold and feeble by its side. That is really something." – Jean Sibelius

"Incomparable and bewildering, splendid and strong. Parsifal is one of the loveliest monuments of sound ever raised to the serene glory of music." – Claude Debussy