Our late-99 Cefiro Elite already has 57K on the odo, so far what we've changed we're the shocks, some bushings, tie-rod ends, one suspension arm (ball joint), and the rack ends... Aside from that, nothing else. We've repainted the car, added 16inch rims (17's or 18's fit well even with big tires), and a Brougham grille and the car looks pretty good...
It's a very stable and comfy on the highways, even at speeds over 160kph although the suspension is more on the softer side. The air-intake box is pretty restrictive, it's probably one reason why the performance feels a bit strained at high-RPMs and speeds over 170kph (for the matic version, the manual reaches over 200kph with more ease).
My overall verdict for the car is that its a good purchase for a 2.0L sedan... it a good car whether you're the driver or passenger.
I posted an extended reply on your query in Nissanbayan: http://www.nissanbayan.com/forums/index.php?act=ST&f=5&t=1238532&s=6fc1e c9e9c876de454e40e6ca78a5b80