I;m not too worried about late march - thats not a bad time of year to be flying. The JFK-MAD flight is a 763 which I find to be inferior to the 772. Bonus seems to be that DFW-MIA is currently blocked as a 772 as well. Don't know if that will hold. I like the AA Lounge in E - I don't know if you get access to that lounge.