The road from the hwy 180 entrance up north all the way down to the Giant Forest area is very scenic and not too difficult to drive.
The road from Giant Forest area to hwy 198 entrance down south is very difficult drive and not scenic enough to make it worth the drive. Plus currently there are 20-60 min construction delays south of the Giant Forest.
Most of the scenic stuff in the Parks are in the Giant Forest area and north of it. Do yourself a favor and avoid the south section if possible.