I live in Europe and my travel takes me several times per year to the US and Asia. So i am fortunate to travel with RTW tickets in F with one of these known low cost starting points. So completely spoiled. And the ability to sleep, a quiet dark cabin. privacy and space is most important, everything else is nice to have.

My TA came up with an extremely good Business Fare from Asia to the US with 2 side trips to South Africa. So i deceided to try Business Class on some airlines.
Even the better Business seats (like on South African) convinced me to go back to F. The only exception was SIA. Their new Business Class on the 380 and the 777 (tried both) is in some important aspects even better than First Class on some airlines.