Don't know how much you have researched, very few operators go there and it is a liveaboard trip. I did the MV Fling a year ago on Memorial Day Weekend. We had pretty rough weather; they postponed the departure from Fri. night to Sat. night..... still rough enough that a lot of folks were getting sick on the ride out that night.
Diving is nice; according to the crew our visibility was bad but still 40-50 ft. Hey, my group laughed because we dive Lake Erie and in relative terms the vis. was great, just bad for them. Currents were very strong during our trip... hand over hand on the mooring line until you were below 40 foot or so. Then again on the return to the boat ladder. According to the crew, during mid to late summer months it can be flat with no current and incredible vis. just depends on the weather. We did one dive on an oil platform; that was a great dive with excellent vis.... I could do the whole trip diving platforms; just an incredible amount of life living on and around the structure.
The staff / crew on the boat were great; food was good; and accomodations were about what I expected from reading their website info. For the money, I would say it's a good value and I do plan on going again some day.
Let me know if you have any specific questions.
Dave