We are renting an RV in Phoenix for 9 days at the end of August. Our current itinerary is as follows: Sedona (1 night) Grand Canyon-South Rim (2 nights) Bryce Canyon (2 nights) Zion (2 nights) ...
We were in Sedona in the off season (mid December) and didn't find it to be touristy or crowded whatsoever. Focused on fabulous hiking, Indian ruins, etc. beautiful place. Worth seeing.