For diving enthusiasts, we recommend Perhentians and Tioman. I was only in the second but I was fascinated diving for free and only with a tube on the Renggis Island of Tioman.
The food is very good. The cultural mix brought by Hindu, Chinese, Pakistani, Thai and Western immigrants has created an impressive culinary variety, choosing from an indecent amount of very cheap dishes. In the more tourist islands the offer is reduced more to the typical dishes of rice with accompaniment and the western ones - hamburger, sandwich and others - but in cities like Kuala Lumpur there is everything.
If you speak English, you will have more chances to have interesting conversations with local people because Malaysia stopped being an English colony just 60 years ago. Most people can speak English which in Thailand is reduced more to the basics and necessary to deal with economic aspects with tourists.
Transportation works very decently - although without reaching Thai frequency and coverage - and life in general takes place at a very relaxed pace. Always depending on which one you want to print, of course.
The prices are basically the same as you can find in most of the countries in the area. Very cheap.
Undoubtedly a place that was very worth visiting and where we would have stayed longer without hesitation. I recommend it to people who are thinking of dropping by this area and have not heard much about it since they live in the shadow of the tourist giant that is Thailand