Elevation of 8,000 feet and 20+ degrees cooler may not sound like good reasons to visit the parks .... but it helped. The parks themselves are spectacular!
It has been 30 years since I was last there and they are every bit as wonderful as I remember ...
The parks cover 865,964 acres, so it is best to choose one region to explore at a time to maximize the experience. Of course, I didn't follow this advice and drove over 400 miles in the one day ....
If you decide to visit Cedar Grove in Kings Canyon, you will be treated to a lush place of tumbling waterfalls, meadows and miles of quiet trails. Half the excitement is the 1-hour drive getting there on Highway 180, which zigzags down into the canyon through Sequoia National Forest. Be sure to stop at Junction View on the way; sheer canyon walls seem to close in around you as the wild South Fork of the Kings River surges over rapids far below.
And I do mean rapids; this is no calm river ...
This picture doesn't do it justice .... where they are really churning there wasn't a photo op ...

Roaring River Falls is less than a 5 minute stroll from the parking lot. During years of heavy runoff, the river pours through the gorge and over the falls with a tremendous roar. Even during the dry season the falls are impressive.
I also found this impressive waterfall ...
At Grant Grove, near the Kings Canyon entrance, you'll see the General Grant Tree. The General Grant is the second largest tree on Earth.
By visiting Giant Forest, you can see the famed Big Trees, including the General Sherman Tree. This tree is more than 2,000 years old and has the distinction of being the largest living tree in the world.
Sequoia National Park was established in 1890. It was California's first national park and is America's second oldest (after Yellowstone).
The lowest elevation is 1,370 feet (in the Ash Mountain area) and the highest is 14,494 feet at the summit of Mount Whitney, the tallest peak in the contiguous 48 states.