I use them from time to time as we have business in Kuala Lumpur, and to get there Malaysian is really the only sensible routing.
They strike me as a sort of poor-mans Singapore Airlines, with whom they are of course in substantial competition for any connecting traffic.
The standards have gone down a bit in recent years, the FAs (notably the stewards) are a bit grumpier than what would have been tolerated previously, and the drinks service is a bit more restricted now in Y.
There are some throwbacks to their Malay origins. On a recent flight from London after takeoff they came round in Y with trays of water, fruit juices, etc (prepoured in little plastic cups), and when everyone had been offered these a steward rushed down the aisle with a tray of similar thimble-sized beers (they must have got about 4 cups out of each beercan) held very low down out of sight and mumbling "beer beer beer" very quietly whilst avoiding eye contact. He was past us all before anyone could catch him, none were served on our aisle at all, and doubtless they all celebrated in the back galley as the Demon Drink was put down the drain
Very nice service in C class if you can run to it.