I did Elite of the Seas, and would recommend them…..I did their highest level of suite available, and it was comfortable and the service was excellent. We bought transportation from Hanoi through them, and it was reasonable, around 80 USD.
Ha Long Bay itself, abit different story as the water ways were filled with trash and plastic bags everywhere.
Personally, it’s a one and done for me. I wouldn’t recommend more than one night on the cruises.