Hkg_clk: Routing via KUL is a really change from SIN. If you like a quiet, but big airport, KUL is the place! This airport was only completed in 1998, making it less than 5 years old. MAS have 18 flights a week to London. Twice daily departing at 10:45 am as Mh 4 and 11:40 pm as MH 2 and 4 times weekly (on Tuesday, Wednesday, Saturday and Sunday) at 9:00 am as MH 8. If you are flying in from Hong Kong, you would probably take the MH 2. But, MH 2 is somesort of a premium flight, where you need to pay more to fly with that flight owing to its popularity. Like ryanair!!! said, if you are departing to London, you are actually departing during the peak hours. Only flights to around SE Asia departs during the off-peak or to the Middle East. During the night, you can see airlines like Qatar Airways, KLM, Emirates, Japan Airlines, Lauda Air, Thai, China Southern parked there and probably a whole lot of others.
Although Kuala Lumpur is situated a little above the equator, it does have some difference in the daylight hours. In June/July, Malaysia get an hour more of daylight more than December/January and that's it. In June/July, the sun would set around 7:30 pm and rise again around 7:00 am.
The purpose for building the runways far away from each other is to cater for the future which would allow aircraft to have simultaneous landing and take off in the same runway. If they build it too close, like in Heathrow, one runway can only be used for take-off and the other one for landings.
KUL was voted as the second best airport in the world last year with HKG/CLK being the first. So, if you fly via KUL, you would be visiting both the world first and second best airport!