There are 2 ways to come into the Phoenix area from I-70
1. Snowflake/Show-Low/Globe/Superior.....
2. Heber/Payson
Both routes have significant grades, but I've had my rig over them both while towing. You will have no problems with either, just have to slow down on the big grades and enjoy the drive. Personally, I prefer the Heber Payson route 100% over route #1. I've traveled that one dozens of times with my old rig. If you have an engine brake, you'll hardly have to touch the brakes except for a very few times.
I live just off Ellsworth in Mesa, so the Payson route brings me almost straight to my house when I take the Saguaro Lake Recreation Area road. Ellsworth crosses US60 just about 2 miles from my house.
As a side note, my MH gets some of the best mileage coming down that road. Not sure why, but suppose coming down those long grades more than makes up for the extra fuel used to climb them!
I hope this helps some. Enjoy the drive......!!!