We flew with Air Asia in Dec. ‘09/Jan. ’10 (HKG-KUL-LGK-KUL-REP-KUL-MFM) and our impressions were good: on time boarding (except for one of the segments), new aircrafts (cleanliness varied), comfortable seats, professional crew and good on-board safety.
There was a clear security issue when boarding, since in KUL LCCT one could board any aircraft in the tarmac ready for boarding, without having his BP checked! Also, the curry smell building up inside the aircrafts became unbearable in the longest flights (HKG-KUL & KUL-MFM).
The KUL LCCT isn’t for sure at the same level of a BRU or GVA, but like the name says it is a low cost terminal! The staff showed inconsistent service levels, but nothing shocking or different from past personal experiences with Ryanair, Wizzair, Finnair, UA or even Lufthansa…
It goes without saying that the prices we paid were 5x lower than what other full service carriers would charge.
In conclusion: for the price, we received what we paid for (on average for the 6 flights).