Shopping in KUL Airport is really bad, everything is overpriced. SIN has a much better selection and better pricing (though I generally try to avoid shopping at airports - they tend to be much more expensive, except when I arrive back in SYD, where alcohol and perfumes (not as much as alcohol, but still ok) are generally quite cheap [and you don't have to lug it around everywhere with you]. There are all of maybe 3-4 shops in KUL - one for cigarettes, one for alcohol, one of all other bits and pieces and maybe a few design shops and a delifrance. Upstairs they have a couple of places - one restaurant and one rainforest cafe. There is also the Plaza Premium lounge which is about US$15-20 for entry. The deli france there charges like a wounded bull.
Processing in KUL is quick, on departure. on arrival it tends to be very slow and tedious, as they never put enough immigration agents on. It is quick - if you hold a Malaysian passport.
My suggestion when you arrive there first is to quickly exit the aircraft on arrival, catch the first available train to immigration, on arrival, exit and take the escalators down and through to immigration, you'll get there before the rest of the passengers from your flight. The trick - get to the connecting train to immigration first! Being slow could add another 30 min wait. The next thing to do is time your exit to catch the connecting KL ekspress which leaves every 15 mins on the dot, take the lifts (on the right) upon passing immigration baggage check on leaving down to the KL Ekspress.
On departure, smooth - they process you at checkin very very quickly, down the escalators, through immigration which are generally very quick (look for the international passport agents rather than malaysian passports). Don't forget to fill out all sides of your immigration form - there is a little bit many people miss at the back with a few yes/no questions.
Once cleared through departure immigration arrive for your flight and give yourself about 10-15 mins to be at the departure gate, as there may be a queue (they need to xray your carryon and metal detector you) then you can hang around in the waiting lounge for the flight (they usually have a TV there playing dead boring (though local) stuff!), the way they do this is similiar to the waiting gate lounges in SIN. If you need to speak to a gate agent about change of seats etc, you must do this before you proceed to the waiting lounge, they are standing just after the metal detectors and baggage check at the departure gate typically.
Malaysia KLIA is generally a very quick place to arrive and depart, with little crowds (except on immigration arrival). It is clean, modern and covered in grey granite throughout. Watch out for the birds (i've never had any droppings on me yet!) in the terminal on arrival, a nice feature!! (they're live - it's supposed to mimick a real rainforest!, but let me reassure you KLIA is boring and very sterile in nature).
In terms of things to do at KLIA, as i've said it is REALLY boring. So try and minimise the amount of time you spend there. If you do want chow and don't have lounge access, I'd suggest getting some food BEFORE you go through immigration, they have a KFC there, and some other noodle, sandwich shops and a Burger King.
If you do want to do shopping, save it all for Malaysia, skip shopping in SIN or SIN, KUL airports, head down to in Kuala Lumpur - KLCC, Mid Valley Megamall (Bangsar LRT Putra station is the closest), and the Sungei Wang / Lot 10 / Star Hill area (near JW Marriott, new Westin, Regent) for your shopping. I've read many folks on here think SIN taxis are cheap, well divide the price you pay in SIN by 4-5 times and that's what you'll pay for a taxi in Malaysia - I almost feel sorry i'm paying them that little - it probably cost them more in fuel! Also, don't miss a visit to Petaling Street in Kuala Lumpur.
[This message has been edited by kawoh (edited 03-13-2003).]