Serge,

all I can say is that the keybed of the PA3X-76 is a dream come true: to me it's the best among the 76 notes keyboards I have played. I still have a Roland G-70, whose keybed is also highly praised, but I consider the PA3X-76 even better: it's a real joy to play and offers the perfect degree of resistance, at least to my fingers. And I can tell you one more thing: contrary to what some believe, it's not the same keybed as the PA2X-Pro, which I never really liked.
Maybe, when you write of problems, are thinking of the Kronos 73 (or 88), whose keybeds used to have defective contacts; that was a real problem, now apparently solved, even if many, just to be safe, buy the more expensive "X" version, that seems to work perfectly.