Latitudes, let me help clarify it all.
Tides is referring to the Pan Pacific hotel in town, there is also the Pan Pac out at the airport.
The airport is in an area called Sepang, it is basically in the middle of NOWHERE. Whilst I can understand why you'd like to do a run, etc and be close to the airport, try and enjoy yourself in town, it is much more worthwhile.
As stated earlier, an 11pm arrival (i suspect u are coming in on Lauda which I do often), you'll have more than enough time to exit and catch the lift down to the KLIA Ekspress after you clear customs. Trains wont stop till 1am last departure, if you're quick and efficient u can save plenty of time and from arrival from the gate you get into the train within 15 mins!
The train fare is RM35 (about A$15) each way and takes only 28 minutes to KL Sentral the downtown. Sentral is like central station in sydney it connects to other train lines (Putra and KTM) and there is a regulated taxi service here. The time you arrive the Putra will be closed so u wont be able to take this into town. But you can just grab a taxi there is a very small surcharge, just go with it, u wont find any other taxi's around here. Try and travel light if you can as ulll get a slight extra charge for using the boot. You pay at the desk first and then they give u a coupon which u give to the taxi driver.
Choice of hotels - as said here, the Ritz Carlton is by far the best and well worth it - around US$60-80 or so for 1 night. Or you could try the Regent or Marriott. I would go for the Marriott. You can then get a good nights sleep and the next morning you'll be in the heart of the shopping area and only a couple of aussie bucks ride from
Petaling Street markets (best after 2pm), and in the morning you could get some food on the streets behind Sungei Wang near the hotel, and perhaps u could even book yourself in for a tour (these are cheap), possibly even out to Batu Caves. I would then stay at the same hotel, but check out around 12am, and then catch a taxi to KL Sentral (or you could try the Putra train if its still open to KL Sentra) and then catch the KLIA Ekspress for RM35 back to the airport. You'll arrive around 1:30am, and about 2 hours before checkin. You can grab some KFC, etc in or around before checkin. If not, u could organise a taxi, but it will cost you at least 3 times more, your choice. Alternatively you could spend ur 2nd night at the Pan Pac at the airport.
Have a lookat
http://www.wotif.com they do have an airport at KLIA listed there. KL is really worth a visit, don't stick urself out in Sepang.
Tim2008 is going to be in town later this month, we should catch up if u want to come along and we can chat further if ud like. Check out FT Community.