we got what we wanted, without having big expectations
All we wanted we got: a private transfer to Halong Bay and a cruise. As we booked the private tour option, we had the ship for our own.
Food was great on the boat (way too much for 2 persons) but outside the tour company. It is prepared by the ship owner.
The tourguide was ok, we figured out she is doing mainly group tours and not really set for private tours. The details were missing, sometimes there were misunderstandings due to the languague barrier. Several jokes she made can be done on a group, but when you are not familiar with the EN-languague - just donˋt do it.
The stop at the pearl farm was completely for nothing (we did not want it, but the tourguide mentioned that the driver needs to have a rest).
Time-wise: it is exactly the schedule for the group tour. As you are always faster on a private tour, the boat was floating on minimum speed just to waste the time (and weˋre not getting back too early). There should be a difference in between the group tour and the private option.
Based on the price we paid it was ok for European Standard and not to discuss. As I started with the review: we got what we wanted.
But if you have more expectations - maybe just book the group tour.