Just a tip...don't go through Phoenix if you don't have to. Get off on Carefree highway, then take the 60 west to the 10 through Wickenberg. Only saves 20 miles or so, but there's always the danger of getting stuck in Phoenix traffic for an hour or 2.
I live a little west of Flagstaff...I actually go west on 40 and either go down through Lake Havasu & Parker, or over almost to Needles and down 95. I think from Flagsatff though, it's quicker to go south.
I've been hammering ice out of my gutters all day...how are things with you?
We're coming from albuquerque and last year we just went I-40, down I-17 around the 101 loop and onto I-10. It wasn't too bad. On the way back we went I-10 up US-95 (on the california side) and then I-40 all the way, just to change it up. US-95 was kinda slow in some parts (windy and going through towns and such). I think this year we'll come down US-95 and then cut across CA-66 and CA-177 to I-10 (I'm looking at goggle maps and I think we'll avoid the little towns along US-95, this way, cool). Looks pretty desolate through there, hopefully the "hills have eyes" people won't flatten our tires and eat us.