We took the 3 day/2 night cruise aboard the Legend, and paid $220/person through our hotel (which was able to give us a 10% discount). We did a lot of shopping around, and ultimately decided to splurge and not do a super-budget cruise (which we heard was really rough) and also not to go super-luxe and spring for the Paradise cruises. We're so happy with our decision! A Class Legend completely met and even far exceeded our expectations, and we felt that it was so worth the money. The room was incredibly nice, with powerful A/C (very key), and was clean and well-decorated. The food, despite what other people had warned, was excellent, and the service was beyond reproach. We'd highly recommend, if you have time, doing the 3 day/2 night itinerary because the 2 day/1 night schedule only really gives you 24 hours on the ship, and you miss the best part of the trip--the 2nd day on the day boat. It took us further out in the bay than the main boat is able to travel, and was a full day of swimming, kayaking, and spending time in nature. Our trip paddled through some caves to a secluded bay full of non-stinging, non-poisonous jellyfish that you were able to touch and pick up. It was one of the most magical experiences I've ever had!
The only con was the long bus ride to and from Hanoi (about 4 hours each way), although that is true of any trip you book, no matter the operator. You do have to pay for additional drinks on board, but I felt that the prices were reasonable (they were about what you would pay for the same drinks from a US vending machine), plus you can always buy cheaper water or beer or soda from the many vendors who will paddle up to your boat in the evenings hawking their wares. When calculating the price of all the entrance tickets (into the Bay itself, to the top of Ti Top island, into the cave), the cost of transport and gas, and the cost of food, I felt that the price of this cruise was well worth it. One of the best and most memorable things we've done on our trip by far!