Hi unsure,
I did this trip in May-June 2013 and it was absolutely fantastic. You get to see incredible scenery in the National Parks, learn about the history of the native Americans at Tatanka, experience a little of the Wild West at Deadwood, learn about the most famous battle of the Indian wars at the Little Big Horn, visit Monument Valley which hasn't changed a bit since John Wayne rode across the plains, and see the bright lights of Vegas. Oh, and I almost forgot to mention the Grand Canyon!
I can honestly say that when we reached journey's end I could have done the whole trip again in reverse order; it was that good. Yes, you do have some one night stops, and I would have liked to have spent a little longer in Cody, but that apart I never felt rushed anywhere or that it was tiring trip....just hugely enjoyable, emotional at times and a holiday that I will remember for ever.
Hope this helps.
Mike