Our visit to Sequoia National Park was a happy convene in being in Yosemite. After that visit - we went here. I remember seeing large trees in Yosemite and asking Tom if they were sequoias, but it wasn't until after we saw one did I realize the sheer scope of these giants.
We drove into sequoia at night, so we didn't get a great look at tree then, but in the morning, we went towards to General Sherman tree, and there they were. It was really hard to comprehend how large they were, and better yet, try to explain that to family and friends back home.
They existed in pockets, and while in the park we saw them quite frequently, there were definitely areas where they took over.
While we were there, we also stopped by the Moro Rock. Not really knowing what it was, we made our way and were pleasantly surprised by the structure. The best part, you can get a great view of the Sierra Nevadas. Unfortunately the city smog made it a bit hard to view in our photo - but in person - it was quite nice.
As a true advocate of National Parks, I will tell you to go and visit - but I would also say that you may not need a few days. However, the trees are a sight worth seeing in your life.