I've experienced that on almost every type of plane including the 777. However, it's not consistant to say that it's the plane. I would say it's the pilot. The only plane I didn't experience the swaying/hard landings on were the 747's. Every 747 flight I've been on(38 or so) have been as smooth as a Cadillac.
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God Bless America West and British Airways
HP - Platinum/800k miles
UA - Dirt/19k miles