We’ve been here over five years. I preferred to get an MM2H visa before we moved here. I think I have explained why in earlier blogs. http://migratemalaysia.com/ is all about MM2H visa, although not the agent I used.
However, some people did it differently. When we were here at first we knew many people who lived here on a tourist visa and simply left the country every three months, and received another three-month tourist visa on their return. Some owned properties here.
For visa eligibility and length of stay, see http://www.klia.com.my/index.php?option=com_content&view=article&id=19
Their plan was simple. They kept an eye on cheap flights six, nine or more months in advance, and booked so they had always left within their visa’s three-month validity. They had a short holiday, and then returned. In this way they visited many countries, and did not have to tie up any money in getting an MM2H visa. It was very flexible.
Anecdotally, this doesn’t really work any more. The people we knew who did this no longer live here.
It seems the length of stay you will get on a tourist visa on arrival depends on the immigration officer. If it’s only occasionally that you come to Malaysia, then you’ll probably get the full three months you get on UK passports, and many others. But if the officer looks through and sees many Malaysian stamps, and can see you are more or less living here, then the length of stay granted can be far shorter.
Thailand Immigration seem to be similarly cracking down on what they possibly see as abuse of tourist visas.
So, if you do want to stay in Malaysia most of the time, now an MM2H visa seems the easiest way, even though at first you have to deal with the application process.
Apparently, though, the Malaysian Government is considering making the eligibility requirements for the MM2H visa much stricter. See here for more details.
The Malaysian Government has always tinkered with this visa, sometimes making it stricter, and sometimes less so. But applying sooner rather than later might be advisable.