This was a very enjoyable, though strenuous, hike. We went in the fall, and the foliage was stunning. The portion of the trail that is on the fire road is very smooth and easy, but the portion that is the little devil stairs is, as the guide notes, strenuous. I am 33 years old and reasonably in shape, and I found that portion of the hike to be quite tiring due to the steepness of the incline. All in our party agreed, however, that the little devil stairs portion, while the most difficult, was the best part of the hike, as you are crossing over the falling stream many times.
One thing to note, which we did not notice until after we were finished: in the trail guide, it shows a path that looks like a figure eight, and it seems to indicate two places where you can start - either from the Keyser Fire Run Road parking lot, or from the parking lot just after the Hogback mountain overlook. The trail then lists the length as 7.5 miles, which we assumed meant that the whole figure eight was that long. However, the 7.5 mile distance is accurate only if you start at the Keyser Run Fire Road lot and skip the upper left portion of the figure eight (including the Sugar Loaf trail portion and Hogback mountain), against what the map seems to suggest. We parked in the other lot and did the full figure eight. We were using GPS to track our progress, and we were surprised to find in the end that we had walked 13 miles. Only then did we realize how the guide was measuring a 7.5-mile trail. By the end of the 13 miles we were pretty wiped out, and it was almost dark, since we expected to be done much earlier. Nevertheless, it was a beautiful hike. The only reason I gave four stars instead of five is because there weren't too many vistas to look out on, though there were some. All in all though, it was a beautiful hike, especially due to the fall colors.