First of all there's no privacy here. I don't mean the opportunity to make loud noises during sex and not to irritate others by it. I mean that you'll hear every damn noise in your room, whether it be some tiny closet in backpackers' area or the largest room of Serenity (like ours).
Advice: don't book the room "Harmony" if you aren't ok with listening to someone's loud footsteps and floor/ceiling creaking right above your head. As I've said before this place is built mainly of bamboo. Yeah, it's so eco and SO not-soundproof. We even had a "bonus" here: right after we complained to the staff about these noises and asked to give us another room, they began renovating a room right above us and a garden wall right next to us. And the only things that we got as a compensation were "sorry!" and "We'll ask the workers to be super-quiet". Yeah, right. I don't say that guys at Serenity are mean, but be ready that they can arrange such stuff as a construction site next to your door and consider it to be totally ok (and eco and serene and namaste/harmony/peace/love/govegan- /etc).
Another not cool thing was them asking us to pay 150 000 IDR for the taxi pick-up from the airport that we didn't order. When we booked this room there, we aked Serenity about the possibility to pick us from the airport. They told us that was possible and named the price. We considered it to be too high, so we decided to solve this problem by ourselves. But Serenity guys still sent a driver to Ngurah Rai to meet us. Well, usually that's a nice thing to be done by your hotel, but not when you're asked to pay in fact double price for your ride. Instead of making some learnings from their mistakes they decided to make us pay them for these mistakes.
Well, it's stupid to live on a tropical island and to expect no insects here. It's a factor you have to deal with.
The "built-in" restaurant is good and has a number of very good vegan dishes, but in a week you'll get bored with their menu (although anyone would in a week). They have yoga classes, but I never visited them, so I can't tell if the yoga teacher is good or like Fabien from GTA V. The place is mostly built from bamboo and has a lot of plants on its territory, so if you like all that "back to roots" romantics (and adore various plants) you'll like "Serenity".
Rooms here have safe lockboxes, which is nice. Our room even had A/C, but we preferred two ceiling fans, because it seemed not effective to run A/C with windows open for fresh air. Serenity also provides laundry services and massage of various kinds (my wife tried it several times and it was good). Bike rental is also available (but it's more expensive in comparison to what you could find by yourself).
Prices for rooms and food are quite low, so the place is good for backpackers