We spent the night in Hana so that we could get to the Pipiwai Trail early when the park opened and have a quiet hike to beautiful falls at the end of the trail. It was a great hike and one of our favorite activities on Maui. The banyan tree along the trail was huge and fun to investigate, and there were several pretty small waterfalls along the path as well, but our favorite part was the bamboo forest. We could not believe how dense and mysterious it was, and when the wind came up, we could hearing the large bamboo stalks knocking against each other. At a couple of places, the bamboo was so thick and tall it blocked most of the sunlight and the trail got very dark. Really a unique experience!
I would rate the trail moderate with a few uphill sections; there were lots of kids on the trail, and as long as you are wearing good shoes (sneakers are fine) and bring plenty of water with you, you'll have a lovely 3 hours round trip hike. On our trip, we were not bothered by bugs at all, but you might want to take bug spray with you just in case. Definitely worth it! Highly recommended!