First I believe that this trail is longer than is written here, probably just above 5 miles. You start out around a the lake. I would NOT call this easy at all. Possibly Moderate to Difficult. I question the tag as "kid friendly". If you've got a great young hiker then yes. Otherwise NO!
Most of the trail is well groomed. You start out on yellow, go on to Teal (Highlands Trail) and back on to yellow. The yellow is very well groomed. The Highlands Trail has places in the middle that are someone overgrown and beware there are spots ridden with poison ivy. I like the Highlands Trail part. It's challenging, some nice hills and ridges as well as babbling brooks. I did not use hiking poles but will bring one if I do this again because as you're traversing over rocks to climb across those babbling brooks you will appreciate that one hiking pole so you won't accidentally grab on to a tree that has a poison ivy vine running up it. (Good idea to have those Technu packs around)
I went on the 6.8 loop on a mountain bike. It starts out nice and manicures, easy. Soon enough it changes to very technical, rocky trails. I found myself pushing my bike up quite a bit though I was there to exercise I was hoping for more rhythm and cadence. There was no scenic overlook but I found it tiring but if you can handle the technical stuff and are in good shape you might want to try this loop. Bring a patch kit or extra tube. Go early or expect lots o flies.
The trail was ok, and the views were great. I don't think I did the full loop correctly, started on the blue trail, went to the top and then connected to yellow/green on the way down. Finished on the blue.
Edit: Went back and did the trail again a second time, and I still managed to get screwed up between the different paths. Apparently blue turns into green and green takes you to the top of the mountain. The markers on the trail are very confusing - they have large gaps between them at times which makes them hard to find, especially when they're crossing over another path. Its definitely not my favourite trail for this reason, but it has the pro of being close to home going for it.
I didn't see a single other person on the mountain, though there were some in the parking lot that appeared to be leaving when I arrived (around 6pm).
The colors of the trails changed frequently and without reason. My 5 friends and I were all baffled and had to stop a lot to reorient. The highest point is such a bummer. It's just a sign in the woods, no view, summit, or overlook. We were disappointed.
I have used this trail alot over the years, both as hiker and hike leader. It is a nice change of pace from the generally more developed trails around it in the park. You get a nice variety of woodland, swamp and stream environments, and some great views. The dogs (on leash) love it. If you have a knowledgeable guide accompanying you, there are abundant historical/archeological remains of 19th century habitation, iron mining and a mine railroad. Most of those features are easily missed - except, of course, the railbed which is part of another trail. There are a number of intersecting trails that offer nice diversions, and this trail is shared by several of these trails which are under a different management. The bears are there, but are generally easy to get along with. I have seen 1-2 bears per hike at times, while often going weeks without seeing one. Most of them would really prefer to leave you alone - or more particularly that you leave them alone. Well worth a morning or afternoon.