Blue Manta certainly looks plush! Its HUGE! To rich for my blood though. I did a trip on the Black Manta (Ambon to Sorong) last year and Cedric was leaving it to take over the Blue Manta. Even though the new CD was new to the boat it still was a great trip and well run.
My opinion differs from frogfishes, there are are some great dives outside the park on the Bali departures, Hot Rocks is an incredible site. It's one of the best sites in Indonesia I've done for Nudibranchs. And If they dive Bima Bay it was really great when I dove it. We dove a sight called Better than Lembeh and it was like 4 sites in Lembeh rolled into one. The second Bali departure trip to Komodo ( both on the Mermaid 2) I did we didn't dive in Bima Bay and instead did some off Sumbawa and they were pretty good also. When I had a frogfish spotting contest on a night dive with my guide we came out with 15 between the 2 of us, I've never seen so many on one site anywhere. That said Hot Rocks, Bima Bay, and Sumbawa are muck dives and I'm crazy for muck.
The dives out of the park off Moyo yes aren't on par with the park dives (they are reef sites). If your not a fan of muck you might be happier with a boat departing from LBJ. But not all the boats leaving from Bali dive the same sites so I'd check each it itinerary, as they say, your mileage may vary.