This Hike is amazing and well worth it. My friends and I did it with a group of 16, with the majority of us making it to the summit for sunrise. Our leading guide was Wayan Widiyasa <email@example.com> who I could not recommend more highly. He arranged 3 vans to pick us all up from our Legian Hotel at midnight and then met us with 5 other guides at Pasar Agung to begin our hike. All this for a price of $300,00.00 Rp per person. BARGAIN!
If you are contemplating this hike I strongly suggest contacting Wayan by email ahead of time and he can help to provided you with any information you may need.
The hike itself was very intense. Even though this is the easiest route, it is by no means a walk in the park. I consider myself to be a quite fit, 30yo male and this was the hardest physical activity I have ever completed. The Hike is 3.5 hours up, 30-45 mins up the summit to enjoy the views, and then 3.5 hours back down. I strongly suggest taking a lot of care coming down on the steep rocky sections. I found this out the hard way by twisting my ankle only 10 minutes into the descent. Luckily one of the guides helped me get back down only 15 minutes or so behind the rest of my group.
This was such a rewarding experience and one that I will truly treasure for the rest of my life. If you are thinking about it, just do it. You will be glad you did.