this is clearly a euro vs americana thing
the seats are firmer as most have said because luxury cars have firm seats now.
what is going on with the seats is the exact same thing that is going on with the suspensions
in the old days, a caddy had springs so soft the front and back bumpers would hit the ground every time you went over a speed bump.
now, modern caddys are just like bmw... very firm sporty ride.
this is why "limos" are almost always american... plush seats plus super soft suspention... maphiaesque.
sign of the times folks