Did the trip last summer both directions, from Loveland to points east in Illinois and Indiana. The portion through Kansas and Missouri were an easy drive, but each state had a unique perspective.
Kansas was much more "wide open space" being more the Great Plains area, particularly as you get further west. And in KS, you've got that elevation change, albeit gradual. And Kansas in the summer is very HOT! Was well over 100 most of the way, so make sure your vehicle is in tip-top shape. Lots to see along the way, and as others have stated, most every small town along the way has a nice city park. With one exception -- Phillipsburg. Not so nice. And that's a shame, because it looks like, at one time it was. Maybe money issues in upkeep? And we also stopped at the Geographical Center of the USA, definitely worth a short hop off US 36 to check it out. Roadway across Kansas was good 2-lane road, with some passing lane sections here and there. As you get further west, it becomes more rolling hills, hence the need sometimes for those 3rd lanes. Truck traffic was not an issue at all, and speeds were consistent, a good 60mph is doable. Keep in mind that, in KS, the little towns seem to be about 30-40 miles apart, so plan gassing up accordingly!
Missouri was a lot different. More trees, more people, more traffic...4-lane all the way across the state from St Joe to Hannibal. Again an easy drive, but lots of up/down hilly sections, not big, just...there. Not quite as hot as KS, but a LOT more humid...very noticeable. Larger towns along the way, more places to gas up, nice small towns, some with nice parks as well, for getting out and stretching legs.
I'd definitely do that route again, sure beats I-70 for stress reduction. Just take your time and enjoy!