I was there for 4 hours
I was there for a long time also. There is nothing to do there. There is free internet though, although super duper slow.
Check in online and drop off your luggage. If u are flying to Indonesia, it is a freakin mad house. Took us an hour to check in cuz there are no dedicated lines like the other flights. I rec to take a shuttle to KLIA to hang out. Better food, nice accomm, etc...