I love this trail! I run it weekly. It has such a fun roller-coaster feel when I can maintain a good pace. I go mid-morning on weekdays and never see crowds. The marked route here doesn't go up U-Mound, though I recommend that you should. It's a great thigh-burner mid run!
The trail is pretty narrow through foliage near the top. During summer, wear pants rather than shorts if possible.
I run this trail every couple of weeks. Since Thanksgiving, there has been snow for the last couple of miles. I recommend poles and shoes with good lugs for traction.
I would not rate this as an easy hike. While it is only 5 miles round trip, the elevation gain is almost 1,000 ft plus there are a lot of very rocks, scree, and ups and downs. It's one of my favorite hikes but it is not for a beginner.