I have lived in, and drove in KC metro area nearly half a century. Stay off I 435. I can't recall a time sense it opened that there was not construction on it somewhere. Now the main mess is near the Mo river, east of downtown.
I 35 in Johnson county, Ks (from about Olathe to downtown) rush hour is from 7 A to 9 P, and it goes both directions. But IMHO most times it moves smother than Dallas.
The main issue going thru downtown is I70 and I35 cross on the same level in a loop right down town. If you watch the signs, get in the lane the sign tells you it is not that hard