rmorton...My 99 Buick Park had the most inexpensive (but new) Hankooks on it when I got it from a dealer. The ride was not very smooth. I had the tires rebalanced and did some rotating and some milles...about 8k. Decided to try some GY TripleTreads.
Well...not much better, still lots of various vibrations especially at around 60-75mph.
Then...the tires got to the 1k mark and they are really coming into their own. Most of the vibration is gone. I still need to have an outer tie rod replaced and will get an alignment and will go from there.