The google maps output said that I-90 vs I-80 is different by 30 miles. That's insignificant.

I've used I-80 in winter and I've used I-90. I prefer I-90 both for lower average altitudes and better pavement conditions. I-80 across Wyoming just gets beaten to death by trucks and suffers from wind exposure.

So if you're driving - I recommend the I-90 choice.