Between Virginia and Colorado, Kansas is my favorite part of the drive. Different strokes for different folks.
Wife and I will go out to KS on occasion and just drive around for a week. The Flint Hills region is some of the prettiest grasslands I've ever seen.
If you're heading West on 70, stop and top the truck off in Salina and then again in Colby - whether you need it or not.
The Flint Hills ain't the part of KS being talked about. That area has merit. West of that, not so much.
And, yeah, gassing up in those two spots is a very good idea.