We visited in the shoulder season (late october) and the whole place was blissfully uncrowded even on a Saturday. There were handful of people. No doubt the unpaved but good roads kept people away. I imagine there are alot more people at Mariposa Grove.
The trees aren't as plentiful and uniformly huge as those at Mariposa Grove but still quite impressive, especially the bull buck tree and the chimney tree. These trees can be visited in a short, flat 2 mile trail. Well worth the visit. A more ambitious 5+ mile hike will bring you to more.
During late October some of the trees are exhibiting fall colors.see photos.
October is also an excellent time to camp here. Lots of open spots and the temps are perfect.
Note the Shadow of the Giants trail is closed in 2018 due to the fires of 2019.