I fly them almost every week and they are usually good. Its true the service is limited but its functional and friendly.
The LCCT in KL is a bit of a mess and is over capacity however the new terminal should resolve the issue. The security issue mentioned I dont agree with becuase I’m always checked either at the bottom of the steps or when boarding.
Its true Air Asia cancel routes and more of this happen whilst they maximise the returns from their fleet. I’d rather fly SQ/MH however most of the time Air Asia are much cheaper and if things dont go to plan then you end up delayed or stranded.
I’ve not lived in the UK for a while so I cant compare to Ryan Air/Easyjet etc