I've managed 5 days of diving in Noumea so here's my thoughts

. I dived one day with Amedee Diving Club and 4 days with Abyss Plongee.
For diving with Amedee Diving Club we got picked up at 0700 and taken to Port Moselle then a rib out to Amedee Island. The group consisted of snorkellers, try-divers and scuba divers. Out at Amedee we unloaded then picked up equipment and tanks and headed out for our first dive. I dived with a friend who hadn't dived for years (but did a refresher before arriving in Noumea). I had my own gear, she used their gear. Same price regardless of whether you use their gear or not. Her regs had no SPG, the instructions were to 'stay at the same level as the leader'... Anyway, Dive Master Didier seemed to keep a pretty close watch on people. The diving had good vis, reasonable currents and plenty of sharks. Back to Amedee Island for lunch and a siesta. Lunch was a tuna steak which I'm told was very nice, the vegetarian option was an extra serving of rice and beans(!) (sauce was nice). I snorkelled at lunch time, lots of turtles in shallow water. Amedee Island was very busy, it was a Sunday and there was a sailing event of some sort there... I imagine it would be quieter and more pleasant during the week. The try divers went out diving at lunch time. Afternoon dive also good fun (lots and lots of sharks!) then back to Amedee... unloaded gear etc.. made it back to Noumea about 530pm so a longish day. A plus of this outfit was that several in my group didn't scuba dive but we were able to have a day out at Amedee Island together both snorkellers and scuba divers. I am not sure I would want to do multiple days of diving with them just as there was a lot of down time - which was great for the one day we went, but I'm not sure I would want multiple days of it. Contatcting Amedee Diving club: responses to emails were intermittent but messaging via their facebook page worked well with prompt responses.
For my 4 other days of diving I dived with Abyss. I contacted them via email & Denys was efficient in his replies. They go out in a rib each morning, 0700 pick up from hotel (if needed) and we left the marina in their rib by about 0745. THe dive sites were 30-45 mins away, first dive, one hour surface interval (with tea and biscuits) then second dive, back in the marina just after 12. I liked this set up as could dive in the morning then spend time with family in the afternoon. Also, in Noumea the wind seems to get up in the afternoon so this allowed for diving when it was calmer. The dive outfit was professional and organised. Price very reasonable (9500 Francs Mon-Friday, 10500 at the weekend, cheaper than a day's diving in NZ, given cost of everything else in Noumea very impressive!). If you get seasick take meds before hand, it could be a bit bumpy between dives. Guides friendly, all spoke good English - briefings were generally given in French & English (I was often only ENglish speaker). Group size varied between a dive master to myself to up to 6 people.
The diving had good vis, plenty of sharks, reasonable hard coral, a wreck one day... turtles, nudibranchs, the usual suspects! Also sea snakes, a leaf scorpion fish one day. No Mantas but was told they are uncommon in winter, not Manta season.
Overall satisfying diving and if in Noumea I thought it worthwhile diving
