I havedriven this route several times. My wife closes her eyes at the switchbacks. The worst part of this road is the overhanging tree branches. I have tagged a few with the mirrors and snagged a branch with my roof attenna (yes it was down and the branch was wedged in).
Absolutely everybody in Sedona, the Chamber of Commerce and State Police say DO NOT TRAVEL 89A in a 36ft RV with toad. In addition to the road itself, there is a very narrow bridge that trucks continually get stuck in. The police say 40 ft is the absolute maximum permitted, we are over that by 15 feet, and even that is pushing it. So thank you all for your advice. I 17 it is!!