Go see the castle, skip the rest
This was one the first hikes I did and I remembered it very steep and somewhat dangerous. Two years later, I can confirm that it wasn't me, it's just bad.
Some enjoy it, but my rule of thumb is that I have to rely on how strong a tree root is to avoid falling down, that's a place I don't want to be in.
This said, the last quarter of the trail runs through the remains of Hachioji Castle and up to the (very panoramic) shrine. It's not that long (about 40 minutes) but pretty and relaxing, so you might do that as a half-day stroll and skip the rest
+ The good
- Takao station is madly well connected, so you can go there anytime
- Ditto for the bus taking you to the castle road: one every five minutes, right in front of the station. You can't go wrong
- Hachioji shrine is lovely and very panoramic
- The Castle ruins boil down to a grass-field with perimeter walls and bridge, but are very well kept and make for a fun walk
~ The bad
- Both ends of the trail are a bit far from the station, so you will need to take a bus or endure a boring walk around the road
- The first half of the walk stands above the highway, so expect car noises to be a constant background
~ The ugly
- Narrow, crumbling trails with steep inclines among dead leaves and fallen trees make for a tense day (although there's admittedly worse)
- The usual green tunnel of plantation trees. Besides on view spot facing Fuji and the shrine, expect no panoramas whatsoever