I went to Fiji on board the
Island Dancer in July 2013. Unseasonal bad weather was bit of a spoilsport and we missed some great dive sites as a result. Still, diving was excellent with lots of coral, colourful fish life and pelagics. We saw plenty of sharks, turtles and a few manta rays. But the trip did lack the 'wow!' factor as you put it and I could not help coming away thinking that I had missed out on the best of diving the place had to offer.
It is very common to hear the phrase "changing weather" in Fiji and it is really true. July was supposed to be sunny with calm seas if slightly cooler water. We saw the sun only sporadically during the week and the sea was quite choppy, which was what limited the itinerary. But apart from that, I found the Island dancer to be a nice little boat - only 10 divers mind - and Capt Joji and his crew among the friendliest that I have been with. If you are going, contact a local divemaster about advice on the best time of the year - the brochures can be misleading.
As for the flight connections, I strongly advice you to ignore going through South-East Asia and/or Oz; the flight connections are unfriendly, the cost high and luggage allowances not always diver friendly. As for the LA route, the airport is Nightmare Incarnate, arguably the worst in the US. I suggest
Korean Air which I used from the UK. London - Seoul - Nadi and so only one change. There are hotels near Seoul airport that you can overnight in to get over the jet lag and if the connection is less than 24-hours, the airline pays for it. There is even a Transit Hotel within the airport on the airside which you can use for sub-24 hour connections with the luggage booked through.
Most importantly, I'll tell you an unadvertised facility with Korean Air; if you book with their London Office directly - NOT using on-line booking or an agent - you get a free 10 kg check-in baggage allowance over and above the 23Kg they offer. Assuming a total of 33 kilos is enough for your dive kit plus personal luggage, this works out cheaper than paying the fixed rate the airline ask for dive kit. From Newbury London is not far and if you have time, trot over to their uncrowded office one day and have a chat about all this; they are helpful.
Finally, do NOT book a flight from Nadi to Suva - a waste of time and money. Suva Airport is over 30 miles away from the city and so it is a hassle. Book one of the many land transfer vehicles who will meet and greet you at Nadi airport, take you to Suva - a quite pleasant 3.5 hour trip - and drop you to the harbour where your boat is moored. I used
Fiji Transfers and they were excellent; the driver even stopped halfway along at his nice house and offered me refreshments.