Thats about the same drive I have to get to Moab (well worth it though!). Sedona is starting to get over built/populated. They are building housing projects right up in the red rock. Kind of makes me sick to see. I was up there in the late 70's when there was nothing but nature up there. The "main" street through town had maybe a dozen little shops and that was pretty much it. Slie rock is a lot of fun and there are some nice camp areas in the Oak Creek Canyon area. Unfortunately they fill up quickly on the weekends. If you came down though, you'd definately want to take your time coming down and hit all the cool stuff on the way down.
When i go to Moab next year I am leaving a few days early so I can stop and do some hiking in Canyon de Chelly (I've always wanted to see the falls and canyons there) and getting into Moab a day or two early to rent a mountain bike and get a little different perspective on the trails!