I climbed it three times in a month. It's so amazing. You start the hike around 2am, and it takes in between two and three hours, plus breaks if you need (plenty of tea and snacks shops along the way). As you climb you can look down and see the lights of the trail, or look all around and see the stars. The atmosphere is fantastic, since it's challenging, everyone supports everyone all the way, the energy is so good. Then you reach the top, with its beautiful temple and people, and wait for the sunrise. And what a sunrise. If the weather is good, it will leave you speechless. And you go down with this beautiful morning light surrounding everything. Truly magical experience.
Warning though, even if full moon (poya) is indeed even better to see, it gets absolutely crowded at this time of the month, which makes the climb not enjoyable at all, it can take up to ten hours to reach the top! Not worth it.