Well 89A is certainly more picturesque, but as I recall coming out of the Kaibab Nat'l Forest into Freedonia, is a pretty good grade. There are a few turns through there, but they aren't too bad. I would think that the step grade would be more of a concern, unless you're handy with gears, which is essentially how you should drive that part of the road. Once into Freedonia you're home free. If you are in the least bit concerned, it's worth it to go through Page. What you'll miss on 89A is the view of 5 of the 6 steps of the Grand Staircase (only place you can see the most of the steps), Navajo Bridge (it's a nice Kodak moment, but the condors are the real draw here), and a shorter route.
Someone here might correct me, but I remember there being a "run off" (not sure what you call it)type road for "runaway" trucks who either have gear or jack brake probs - that sort of tells you about the road coming out of the Kaibab Nat'l Forest.
You can always take the Page route, then take the towed vehicle back through 89A. You should try and make that trip since you're there. Also at Kanab is the geological ranger station for the Grand Staircase Escalante National Monument. Also this is where you get your pass to hike "The Wave".
Here's a little video that will blow your mind. But even if you don't get a pass, go through the station cause it's filled with great info about the geology of the area.
