I seem to have a excessive amount of up and down travel on unlevel surfaces(97 STS).
The ride is nice on smooth surfaces, but hanldling is not what I think it should be with the ride
control and other technological innovations. Any help, something I can check.

signed disappointed

 

you might need to check your schock absorbers. If they dont work correctly then when you go over a bump or anything that causes force on your springs then it will bounce up and down. You can check it by pushing down on your front end and see if it bounces a couple times, this indicates its worn out.