Sedona is just an amazing place to see. The mountains are beautiful and red, and it's fun. There is some shopping, so your wife will be happy - and the "Cowboy Club" restaurant is good.
However, after spending the day wandering around, you may get bored if you don't drive down the canyon or take a tour.
If you go to Sedona, you will be close to continuing on along I-17 to the Grand Canyon. Have fun.