tread rating and comfort

i've had this '97 buick skylark almost two years now and want to change form the Toyo Ultra Touring that i have now. they have exscellent handling but i think are a little stiff.
the tread rating is 700AB with a 100K warranty.

i want to get coopers:
SLE 620AB 70k
STE 700AB 85k
SportMaster GLT 360AB 50k

i want to keep the handling and pick up some comfort.
the STE is probably close to what i have, huh?
a very low treadrating means - good traction AND ride comfort?

thanks

al

try adjusting yuor air pressure ... alot of people a local tire shops over inflate tires because they don't know any better and size the sidewall says "max presuure 51psi" that's what they put into the tire