Pros: Good food, strong English proficiency. Good diversity. Easy to get into the top 1% of tech. Very easy to set up a non-VC backed company, and you'll make sweet margins.
Lots of talent, roughly equivalent to Singapore. They have NUS and ivy league grads, but we have the population funnel. You can have all the smart conversations you have on HN all day and all night with someone out here. Plenty of tech events in KL, probably comparable to European capitals.
Cons: Middle income trap - retiring with a job is extremely difficult; most either end up doing a business, working in gov, or staying as a corporate slave long enough to get a VP position. High sin tax (alcohol, tobacco). Work discrimination is fully legal. Affirmative action is also a heated topic. Uptick in racism as we go through some political shifts, but it's still decent IMO. Very little VC funding here. VCs prefer Singapore, Indonesia, Thailand, but VC-backed companies often set up engineering/R&D offices in Malaysia.
Mixed: There's good tolerance of LGBT+ here. Violence is uncommon. However, it's tolerance, not full acceptance. Don't force your views on others and you'll be fine. Everyone has very different religious and political views from their neighbors.
Stats say crime rate is comparable to Canada, but I think it's mostly the poorer areas. KL is mostly gentrified now; most of the people who would be delivering drugs are now delivering McDonald's.