I started hiking the CCC trail by parking my car at the top of the hill in the parking lot near the Visitor's Center. I then hiked the CCC trail down to the Amphitheater, then crossed the street to hike the Pioneer Nature Trail loop. I then hiked the CCC trail back (uphill) to my car, which provided a good cardio workout.
I found the CCC trail to be very scenic. The views from the ridge are very impressive. It is a short hike that I would definitely recommend.
By contrast, I found the Pioneer Nature Trail to be disappointing. It really didn't impress me in any way. It's just a short dirt trail to walk on and not a trail I would recommend.