I flew with Air Asia SIN/KUL/SIN last week and it was interesting to note the number of business travellers on board. I think that a lot of business travellers are now shunning the legacy carriers and taking the cheapest option - certainly on short haul. That has to be good news for the lo co's.
Cabin was clean and tidy, cabin/ground staff were polite and efficient, both flights ran to within 5 minutes of schedule and our bags were waiting for us as we arrived at each baggage carousel. As a business model, I would say it's working very nicely.