I was there as well and thought it was wonderful. The last time I saw Victor Garber singing live was in the production of Damn Yankees, and he was just as wonderful 20 years later.
I thought the whole evening was magical, and I don't know why, but I was amused by the somewhat raucous reaction to Queen Latifah (who did a fantastic rendition of When You're Good to Mama.
In addition to Victor Garber (who was the impetus for me to purchase the ticket), I thought Laura Benanti was fantastic and I can not wait to see her in Roundabout's She Loves Me. Though those were my favorites (well, Queen Latifah kind of knocked my socks off), everyone seemed in fine form, and while I'm not an opera fan, I was glad to get the chance to see Renee Fleming.
My one quibble was not with the show, but with the venue. I was sitting in the Parquet about four or five rows from the stage and the sound sometimes seemed muddled. I know that the Tiers are generally the best places to hear in Carnegie Hall, but I was still surprised that it was not clearer. Still, a minor quibble for a well-worth it evening. Also, the woman behind me tried to sing throughout Alan Cumming's opening number (Wilkommen). Luckily, I was not the only one who expressed my immense displeasure. She did not try again.