I spend a lot of time diving PNG and have been on both the Dancer and FeBrina. The Dancer may be bigger and more comfortably laid out, but I fear she has gone a bit downhill since leaving Peter Hughes.
I much prefer the FeBrina for many reasons. Although she is smaller and you do have to climb ladders to the staterooms, I just love that boat. She gets into areas no other boat does. More importantly, she is captained by Alan Raabe who has forgotten more about diving in PNG than most captains will ever know. He has plied those waters forever! He is very eco friendly too. He has put most of the permanent mooring in the area to keep damage to the reefs at a minimum.
I've been with the boat in New Ireland, north shore of New Britain/Witus, Rabaul/Duke of York Islands/Gazelle Peninsula, and the South shore of New britain.
If you are bazarre little critters, the south shore of New Britain is really good. For great everything-big schools of fish/sharks/ critters you can't do better than Kimbe/Fathers and the Witus. That is the best itenerary, IMHO.
Be aware that locals will paddle their outriggers to the dive boat to trade food and just "hang out". They will often bring the kids to see the divers.

The kids LOVE it when you bring "lollies" (candy). The also like getting gifts of pens to use at school.
Women need to be aware that PNG has some cultural taboos. While locals could care less if women go bare breasted, there is a real taboo for women to bare themselves from waist to knees. Keep a lap-lap (sarong) to wrap around yourself the minute you take your wetsuit off and try to not walk around the boat in your bikini, when the locals are around.
The Fathers (dive area) and the Witu Islands (Garove Island) should not be missed if you can make it happen. The Witus are often hard to get to in rough weather. Incredible diving.




I hope you have a wonderful time, no matter which boat you choose. I would be happy to talk with you. I have free calling in Continental US if you want to chat about PNG.