Even though some ani-miles are more equal than others, I believe it's anyway interesting to have a look at the AF/KL cards offered by Beobank. They yield 1 mile / eur for the basic and 1.25 mile / eur, for the premium card. That's much better than the previous SN Mastercard at the end of its life (0.5 mile / eur). Within the AF/KL universe, it's almost the same return as the Dutch/French AF/KL AMEX (1 for gold, 1.5 for plat) and much better than the Swiss AF/KL Mastercard (0.5 miles per CHF).
Beobank cards are actual credit cards, not charge cards, so I suppose they also finance the miles with interests on the unpaid balance, in addition to the transaction fees.

This gives me some hope for a decent return


Back to the AMEX switch offer, I agree the booster is generous. While I obviously don't like the increase in yearly fee vs the SN branded card, quite a lot of OPM expenses go through my card so it remains worth it, in my current situation.