...and Now for Something Completely Different
If you plan to spend significant time in southern Utah seeing a bit of the Mighty Five, you can also visit the Grand Canyon and get quite a different feel for it than the usual visitor. That's because the usual visitor goes to the South Rim which is more easily accessible from a major Interstate, has a drive that follows the rim for a significant distance, and has more services. All good reasons, but also a good reason to visit the North Rim which is not as accessible, has only a single road in/out, and has fewer services. All that simply means that the North Rim sees far fewer visitors and is a much quieter, more natural, and more serene place to enjoy the Canyon. I would not write off a visit to the North Rim just because you've 'done' the South Rim.
AZBuck