I did the dive safari a couple of years ago on my first trip to Ph. Although it was fun I would be neutral on recommending it. Some of the things I did not like were that there is no nitrox, the boat ride is long and the boat was not very comfortable, there is about 4-6 hours of boat ride a day, there were not a lot of good places to relax and take a nap on the boat. You are stuck on the boat with the same group of people for 6 days, although you do get off at night.
Some of the benefits are that it is a fun adventure, you get to dive a lot of different locations which would be difficult to do any other way since you would have to take multiple flights, the crew and the food were good, you get to see several different towns but only get a short amount of time at each one.