Well, I had a great time on Qantas!!
Recently flew SY-LA-ATL-Miami and return, with Qantas for the Pacific legs and Delta for the US domestics.
Qantas was wonderful. Good food, good service, happy and helpful cabin crew, comfortable seat pods in business class.
But Delta was a shocker, even travelling first class. No lounge facilities for my class of ticket, and I even was told to buy some food and drink for the 4 1/2 hour run to Atlanta. The aircraft were old and unloved and the crew was run off its feet just tossing peanuts at the punters. No pillow, just a rug in a plastic bag.
On the way back it was such a feeling of relief to step into the Qantas lounge and the Qantas plane.