As a KL expat for 10 years, take this advise

check in your bags in person, it makes it WAY less likely they will be lost or stolen. Also spring for the plastic wrapping at KLIA, you wouldnt believe the luxury goods I have 'lost' over the years at KLIA.
Great airport, people and Airline, but the baggage handlers need some more oversite.
And I can concurr checkin is anytime, and the Golden lounge opens before the first flight of the day for MH and closes VERY late (last flight leaves at like 2am)

I still miss SZB....bring Subang back!