Upvote:5
If your priority is trying to avoid slopes as much as possible, you might opt for I-17 to Flagstaff and I-40 to Holbrook and then down 77 to Show Low. It's a somewhat longer route, but it's mostly on nice wide, flat and fast interstates, rather than the mountain roads on your two suggested routes, and these are more likely to be free of snow (or at least well-plowed).
Upvote:13
If you put it into Google Maps and select "bicycle" instead of car, you will get an elevation profile of the route.
By the looks of it Globe is more of a steady climb whereas Payson has some local peaks
Upvote:13
I've driven both routes many times. The route through Globe takes you through the Salt River Canyon (Google it!) That would be a nightmare with an RV. I'd opt for the route through Payson.
Both routes are awful if it's been snowing, and you can get heavy snow (enough to close the highway) from November through March.