The inner loop makes this a very challenging ride for the average rider.
Grades are long and steep.
You need technique to keep the front wheel on the ground going up and to keep your body off the ground going down. Shooting up one hill, you risk becoming airborne at the crest just before a sharp left turn. Sometimes there will only be one good line on the downhills. There is no level ground on the inner loop. If you can handle Murphy, there are many rewards to riding it.