I have flown with Swiss Air on a couple of occasions. Once from Sao Paulo to Zurich and then to Warsaw. The other time was from Warsaw again to Zurich then to Rome and finally to Sao Paulo.
I could not fault them at anything. Both the ground-and air staff were very friendly. In fact when I booked my ticket I had to cancel flights and re-book. The staff was very helpful. My only criticism: it took 6 months to process my refund. I am not sure if this is the normal time period.
Their aeroplanes are new and comfortable. Everything was in working order and I loved the Swiss chocolates that they have on board! They make you feel very special.
Definitely a World Class Airline!