The loop is definitely a very convenient way to explore the park if you are short on time...and they also have parking lots at major vista points which is very nice. Each vista point also has a variety of trails that you can choose to explore, but this is where I was a bit torn.
Paths are unmarked which is great, to show that nature was generally undisturbed...but for someone not necessarily adjusted to fairly rocky terrain hiking, it did limit us to what we felt comfortable exploring....and it wasn't much, given that maps weren't even accurate for some paths. And in choosing to stay on the main road, it just didn't feel like you were a part of nature. Literally, you drove from site 1 to site 2, parked, and snapped a few shots.