Fantastic trail. One of the best places I've hiked in the state. There's so much to see and there's no crowding at all (in fact, hardly anyone on a beautiful June afternoon). Not nearly as rough as the trail guide would have you believe. The streams are inconsequential and I can't imagine them posing a problem to anyone unless it's been raining for weeks or something. Rock-hopping is plentiful. The trail gets a bit sketchy around the first waterfall and I lost the yellow blazes for a little while. Otherwise, it's the most fun dayhike I've been on in a very long time.
Not much wildlife, just deer, rodents, a snake, and frogs. Common birds, mostly, though hawks are common in the higher areas of the trail. If you're too winded to continue after High Point, the trail's first peak, you can cut your hike short and head downhill on the blue blazed trail, which cuts your total trip to about 2/5 of of the 9.3 total miles. If you decide to continue, the trail gets much easier after high point. Definitely worth doing in its entirety, but if you're not very fit or hiking with children you'll still have taken in most of the really-cool scenery by High Point (such as the mines, a waterfall, and the good views). It's also best to start early.
Another point I should mention is that the driving directions are preposterous and routing you through Ringwood via Skyline Drive is absurd. Proceed to exit 54 (not 57 like it says) off 287 and take Route 511 North to Westbrook Road, then left at the fork and Snake Den Road will be on your left.