Communication with provider is bad. They do not reply to the contact numbers provided. It was not clear when booking that the transport is a minibus and that you have to arrange with them pick up and drop off points. Take into account that they do not speak english and you may need help to communicate (if you manage to find a different telephone o contact line). We managed to get the number of the driver and our hosts at Malang helped us to communicate.
Arrival at pick up point was 2 hs late, you have to have faith they'll arrive.
There is little space in the minibus for @12 hs trip. During the trip the driver will do a couple stops to use the toilet and also to have dinner. Dinner is included in the ticket price.
If you're claustrophobic crossing with the ferry closed in the minibus without space to open a door could be a problem.
In general we arrived safely to our destination, but would had been good to jave all this info before the trip.