The Outer Loop's biggest challenges are the rocks. There's not much let up of jagged edges under foot. Other than that, it a well-marked (when you can pick your eyes up) singletrack with good climbing as well. It doesn't seem very busy, but I went when it was 40-degrees F. You may have to jump a couple of fallen trees but nothing major. Also, don't expect any lake views along the trail, but you'll come across some interesting passes through boulder formations.