I agree -- the Weber 5751s are rock hard. However, I disagree on your opinion of the MD-90 seats. I think those are also rock hard. I like the MD-88 seats (though the recline on those could be better), and the seats on the PMDL 757s with 24 F seats and 26 F seats. BTW, the 764s don't have the Weber 5751. They still have the good (comfortable) seats.