to be fair,jap cars nowadays are pretty good in almost every way.even design-wise,they have come a long way.
as far as ride quality is concerned,very true that the Camry,Accord and most new jap luxo-barge rides very well.in fact,contrary to Funfer's daughter's view,i think the Camry rides even better than an e60..i should know.
but all these japs lack that one important trait..body control.eventho the Camry(hell,lets pull in Lexus as well)rides a little better,it just lacks the body control of the Contis,especially when u're pushing on.
again,to be fair,the new Accord and the Camry are very very good cars..if u don't intend to push ur cars,by all means.both Jap and Contis have their strenghts and weaknesses..choose based on ur own requirements and criterias.