Aitutaki(spelling?) was more my scene than Raro-after my first dive there the DM used it as an excuse to have a beach party!
The place is mostly deserted-even in the height of the season. There were a few soft corals coming back-mushrooms, leather corals and some other weird things. A few table corals and some acropora. I saw pipe fish in a breeding dance and a few lionfish. Some caves-i LOVE caves.
Cars with no panels, doors or windows. A bank that only opened tuesday for 4 hours. The friendliest locals. It's like Raro but tiny.
One foot island is pretty cool too. You can get your passport stamped in the post office there-the only building on one foot island.
Some of the outer islands in the cook chain are still inhabited by cannibalistic tribes

Which is v cool, unless you happen to get invited for dinner.
But Raro is a great place. It's always warm-even the rain is warm. Island evenings are quite fun. I had the biggest cocktail ever in Raro-it was served in a goldfish bowl and had every spirit in you could imagine. The food in the restuarants there is amazing. Mostly seafood but i love seafood. I recommend the Flame tree by Muri beach. Gecko's are everywhere and i love Gecko's. It's warm. Did i say it's nice and warm? I snorkelled about every day and see puffer's, octopus and a miriad of butterfly fish. Speed limit on the island is a little above walking pace but there were one or two Subaru imprezza's? Couldn't understand that??? Hooning about on mopeds is fun. As is getting your Raro driving license. Overall Raro is a great place but the reef's are gone-totally wiped out. So if you want to see pristine reefs forget it. Otherwise it's a great place. I'd definately go again. But i wouldn't take my dive gear, i'd just snorkel. We were there for 14 days and it rained for 12 which meant you couldn't dive as the run off made the surrounding sea's completely brown and zero vis. So i utilised my time drinking, eating and meeting locals. Loved it.