I've done the Dolphin Dream twice - once for Spotted Dolphins only in 2009 and once in 2014 when I did a combo Tiger Beach and Spotted Dolphins.
I also think highly of the DD and agree with all the comments made above: the food, the crew and the Captain are right up there with those on the better liveaboards. But compared to most international liveaboards, when it comes to accommodations (cabin comfort and space and just two shared bathrooms for 10 (maybe12) divers), it is a bit Spartan..........assuming these are important criteria for you.
I also did the Great Hammers land-based with Neil Watson in 2017 for five days and would not hesitate to do it again with them. They are based at the Big Game Club in North Bimini. We stayed in a condo (was called the Bimini Sand) in South Bimini but Neil Watson was very accommodating in arranging for the dive boat to pick us up and drop us off at the marina of our condo everyday. They are an excellent dive operation, but if you end up having to stay at the Big Game Club in North Bimini, it was pretty pricey back then, and on top of that, their restaurant prices were pretty steep as well.
We saw Great Hammers everyday, some days up to 4-5. There were loads of Nurse sharks lined up in front the feeder looking for scraps. Bull sharks tended to stay at a distance and if they approached, the dive crew banged the bait box to drive them away.
One thing worth noting regarding the great hammer diving day with Neil Watson's operation, at least as it was done in 2017. Each diver was assigned two tanks. Since the dive was done in 25-30 feet depth, with two tanks, air should not have been a limiting factor when determining how much bottom time of Great Hhammers you got. The limiting factor was the amount of bait they had. Once the feeding started, it never stopped - ie, there was no break built in to allow divers to change tanks. That's understandable because if the feeding stopped, the sharks would then lose interest and leave. On most days, the bait ran out in about two hours.
Those who were really good with air could squeeze two hours out of one single tank and therefore stay the whole feeding time. But if you had to change tanks, you lost that amount of time it took you to ascend, swap tanks, maybe get a sip of water, and then descend again.
I don't know how this compares to how DD does a full day of Great Hammers.