I70 has tolls in Kansas so you don't gain much there. Kansas also tends to be windier than the Northern route across Nebraska. There are a number of attractions across 80 including the Kearney Archway, Antique Archaeology, museums, and others.
Won't be long and there will be periodic snow closures of the highway. If you are taking 70 west out of Denver you already have possible daily short term highway closures due to snow.
Roger, Dawn, and Roxie