I realised that I hadn't really given any explanation for my rating yet, so here it goes:
Well, in short, I really love the pack!
I am having so much fun with it, I really can't stop playing. I first spent a few hours in B&B and CAS - and in this respect, it's especially impressive. In terms of gameplay, I think there's quite a bit you don't see at first. But what they did give us is, for the most part, very well done. The lot traits, the mermaids (<3), the sim traits, the new activities, the volcano, odd jobs, the overall feel of the world and its people, etc. are all great. The conservationist career seemed weird to me at first, but it's actually relatively relaxing and, somehow, I really did end up caring about how "dirty" Sulani is xD So, so far, all my Sims want to help fixing it (both the sea loving mermaid, her daughter and Makoa, as well as the tribesmen- and women). It's just overall really relaxing and fun. And addictive ?
But there are omissions. Personally, I wouldn't want there to be lots of tourists in Sulani from other worlds (especially not famous ones). I like that most of the sims I see there are from that area (with a few exceptions). I appreciate that. But the option to buy a second home, and to be at least a semi-permanent resident of Sulani would have been cool. Because what if I wanted to make a writer sim who loves the culture and nature of Sulani, but only lives there during the summer months? Or a sim that would like to buy her late parent's place to keep it in the family? Or a sim who just likes to own a vacation home? ? I mean, it's just a nice feature to have and I don't see why they can't implement it using a similar mechanic to the one they already have for retail stores. I also miss group activities (I'm glad sims can build sand castles together, but having two sims on the boat or playing volleyball or tag together on the beach would have been great).
Now, for me, I still find it an incredibly fun pack, despite those omissions. I've been having such a blast lately playing this game with mostly larger groups of sims (a military, a supernatural orphanage and a fishermen tribe all together in one save? Hell yes ?). And Island Living adds a lot of new, fun storytelling potential that you can go a lot of ways with. Which is why I give it an 8. But: island life (not island vacations), environmentalism and mermaids kind of have to be your thing for this to appeal to you. If it's vacationing and doing standard free time activities only that you want form a tropical pack, basically "Paradise", I don't think this is that. It really is the "Living" there that's fun here.