You are going to see the Great Plains on either route, more so on the southern because I-80 and I-76 follow river valleys.

I-70 in Colorado is indeed scenic (this portion, anyway) but it would be shame to blast thru the canyonlands of Utah and not take a detour off the interstate (Capitol Reef, hwy 12, Zion, etc.).

It's hard to read, "I absolutely love Hyatt Places" and think that you're not taking the piss.