Sorry you had a bad time Klynch. I was on the Kona Aggressor back in February and really enjoyed it. I wouldn't say it was the best diving I've ever done but well worth it.
I particularly enjoyed the night dives. We ended up doing two Manta dives and "Pelagic Magic." Pelagic Magic was unlike anything I have ever done before. It took me a while to warm up to it but about 10 minutes in I started spotting many different zooplankton to keep me entertained for 45 minutes. Unfortunately most of the other divers bailed before 10 minutes and by the end of the dive it was just myself, another diver and Captain James remaining in the water.
I agree that the manta dive is circus. I counted 13 other boats at the site before we went underwater. I thought this was where the Aggressor shined. We were able to wait out all of the other boats, since we were going to be moored there for the night, and for the 2nd half of the dive had 20 mantas to ourselves. I am not familiar with the land based boats off of Kona, but from what I saw the Aggressor is the best way to do the manta night dive.
One good thing about going in the winter is whale season. We actively went whale watching during our surface intervals seeing many pilot and humpback whales. We also saw many spinner dolphins.
I thought the crew did a good job. Captain James really impressed me running around skippering the ship, taking video, leading dives, and pursuing whales. I don't think he slept. The food was great, prepared by chef Chris, and I really enjoyed diving with and getting to know Hale (who I thought provided a lot of humor), Dave, Mindy, and Matt.
The one flaw I found was that crew was over worked. I have seen this on other liveaboards as well and may explain why you didn't see "humor,unity or genuine pleasure shown in their work." Personally I think the crew should be given Friday afternoon off and cancel the cocktail party. Most guests wanted to get on land and see a bit of Kona anyways. It would go a long way to make a happy crew which makes happy guests.
I would recommend the Kona Aggressor to other divers, at least from my experience.