As the others have said, by and large AirAsia is somewhere in the region of being on time - well usually within an hour of scheduled time anyway. I've only had a couple of delays longer than an hour and one cancellation overall in well over fifty flights on AirAsia.

So long as you set your expectations appropriately then AirAsia's fine for an hour or two flight, just make sure to have backup plans if you're planning to connect to any other flights. The LCCT at KUL is a bit of a zoo too, for an extra bonus in relation to the LCC experience.