First off, I would highly recommend this place as a weekend getaway from the city. You will be impressed with the details that have gone into the design of this place. It is pretty much a mom-and-pop-establishment, run by the founder, Mr Rubin, and his wife, Michelle. By the end of my stay (only one night!) I felt like I was leaving my uncle/aunty's house, and felt sorry to have to go so soon! They were very kind and concerned about my safety as I visited this place alone, and lent me a walkie-talkie so that I may contact them incase of any emergencies during my stay. They chatted with me and were very good company.
Cleanliness is as good as it gets, but please keep in mind that this is the middle of the jungle so expect some ants here and there in the outdoor bathroom! Not a big problem though, as I'm not squeamish about the outdoors. (I did not encounter any hostile critters during my stay, thankfully.)
I stayed at the Reading Rock tendor (tent+pondok) and it was a very good experience. I slept through the roar of the river just meters from my door. The room is exactly what you'd expect from a glamping trip, clean and cozy, and came equipped with mosquito nets all around. There is a small fan but most likely you won't need it as it can get chilly at night.
As for the activities, there is a river for you to splash around in, and also the Chilling Waterfall a few minutes walk away. I saw other guests doing yoga out on one of the pondok spaces. You may also go for a hike in the surrounding jungle. Reading is also a good option, so do bring a book, and also get ready to make friends with other guests there. Basically everyone is just there to chill and leave the concept of time behind them. =)
Only one minor point of improvement/suggestion that I have for this place. As I traveled solo, I took up the meal offer of RM90 for Dinner and Breakfast on-site. It was delicious and convenient for me, because I did not want to drive through the jungle in the dark, but I would not recommend it to those who are travelling in groups, as you can drive 20 mins to KKB town and find something with more value for your money there.
Final words, yes, definitely do give this place a try if you love the great outdoors. You won't regret it.