We just got back last Sat from a two week stay in Taveuni w/10 days of diving...I have no pics so won't make a 'formal' report, but we'd also recommend it for diving.
We stayed at
Makaira by the Sea (just two bures, great view, unforgettable staff, very good experience...recommend it) and dove with
Vunibokoi (shocking website, they're better divers than webmasters

)...Tyrone Valentine is the owner/operate of Vunibokoi and is very experienced...we were very impressed watching him instruct two teenagers on our trip...he had them diving like pros within a few days..Also, We gathered that there has been some movement of dive staff on the Island due to the closing of Swiss Divers (re opening soon w/new management)...and the guides we had were mostly new to Vunibokoi, though most were very familiar with all the sites. In particular, the boat Vunibokoi had was good...we had up to 13on it a couple of days (10 divers + 3 crew), but often just 4-6 of us...
Food wise, we second the recommendation of Tramantos restaurant for pizza (Makaira is on the cliff above Tramantos) and Tovutovu for day to day eating, esp after diving (Vunibokoi is based at Tovutovu)...Also not to be missed is Makaira's Tues night Seafood night...John (co-owner) is a great fisherman and handy in the kitchen with superb sashimi, chowder and various delicious fish dishes...
...and to the important stuff...diving was good...Unlike the other posters here, I was underwhelmed by the Great White Wall (dove it twice)...Nice, but not breathtaking...Rainbow's End, Rainbow City and Fish Factory were our best dives in the Somosomo Straight...but I was also very impressed with diving around Qamea Island...nice walls and some deeper bommies, excellent soft coral...but go with a guide who knows the area as there are some streches of barren sand and dead coral in a couple of places...All up the diving was very good...the variety of coral was impressive...as were the reef fish...no many pelagics/big stuff, but we were OK with that ...The diving was not quite as good as what we'd seen in the Solomons, but certainly world class.
I'd definitely go back (if there weren't so many other places I also want to see first)