Langkawi is very "laid back". No "sex industry" like nearby Thailand, cheap alcohol (tax free), food is cheap and I found some nice restaurants. There are only a few malls on the island, and none of them is really big. Only one cinema on the island..

Plenty of "nature" things to do, but weather is a big factor. I'd say without a rental car you're lost. Rental cars outside of high season are super cheap (40-50 MYR per day) and traffic is very, very relaxed compared to everywhere else in Asia.

There are a few high-priced, top resorts on the island, some decent 4* properties which are reasonably cheap, and plenty of cheaper basic accomodation. Getting around the island is really easy by rental (only one semi-highway across the island from the airport to Kuah town) but everywhere else, you need some driving skills.

During good weather, Langkawi is awesome. If you happen to hit some rainy days, it can quickly become less interesting.