My experience with JavaJivi was nothing short of excellent, from organising the trip through Rangga to visiting Mount Papandayan. Mpu was very knowledgeable about the volcano and took me to some amazing location that I would not have gone without a guide. They were able to pick me up from my hotel at 3am and drop me back after as a solo traveller.
I highly recommend Papandayan for anyone looking for a less touristy indonesia, go on a weekday if you can! Had the sunrise location and craters to ourselves. If you're visiting Garut or Bandung, contact Rangga and organise this, it was the highlight of my trip.