Correct, Ivanko, the status is much easier to achieve (at Delta I need to collect 60 legs for gold, not 30 as with CSA). But with Delta, once I am gold, I also receive 100 % more miles for every flight. So I guess for me, as a long-distance traveler that is quite interesting.

I was actually considering Flying Blue when I was switching from OKPLUS, but I never could find the qualifying rules and what booking classes apply etc. In a way it was similar to CSA problem with clarity of information we discuss here. Delta is straightforward and absolutely clear in this.

And... You are lucky that your employer is willing to pay the high price tickets for you. I just would not be willing to pay 10 times more for a ticket myself only to get the miles. I do pay a little more to fly with KLM or AF around Europe and don't mind the transfer; also because I can rely on them more. (Unfortunately, I had to many cancellations and schedule changes with CSA, that I do not feel I completely trust them. They always reimburse the ticket if they have canceled a flight, but then it may be too late to redo my plans. )