Fantastic hike. I did it back in late 2013, and would have done the grand loop that included the cliffs trail as well as the Awa'awapuhi but the cliffs trails had just been closed.
The first about 2.5 miles are not that bad, but it is a constant down hill. After that the come out of the forest and are greeted to some amazing views. After you past the Cliffs trail intersection the views down into Nualolo valley are simply stunning.
If you can stomach it, make sure to make the trek to the Lola Vista, the trail gets far more treacherous, at one point are are on a rather thin ridge and a slip in either direction would result in some serious pain or maybe even death. But once you get to the vista the view is incredible, seeing all the way down the opposite side of the Nepali coast.
If the weather begins to turn on you make sure to get back to the forest portion fast, it turned on us and we experienced a solid 2 hours of constant, often torrential rain all the way from the edge of the forest to the trailhead. The trail begins to get difficult to traverse because the trail became a log flume but at least we were out of the open where the risk of falling only meant a potential scrape or bruise.
Breathtaking. Be prepared to FOCUS as there are narrow paths on incredible heights. Be in good physical condition. Elevation not a factor, but the grade is. Pack appropriately. Start in the early AM. Last half-mile push is significant: views, winds, height, etc. Incredibly rewarding.