When I checked with Marriott about 2 months ago, I was told that 250K in Marriott points would be worth about 80K in FF miles if simply transferred. However, if combined with a hotel stay, it would be worth 7 days at the hotel plus 120K in FF miles. I'm thinking of taking it with the thought of tossing the very poorly reviewed Renaissance in Jerusalem. I want to use up points both in Marriott and AMEX before they devalue further. Two years ago, I took 2 FF seats on Air France to Geneva at 100K each. Now they are 160K if available. 120K gets only Business Class.