I've flown OD DMK-KUL twice. All's fine other than a small delay the second time due to late arrival of the incoming flight. Also flown the BC product to HKG.
Nice pluses are (even for the back)
- complimentary food and beverage
- generous checked baggage allowance
- Check-in rather quick and you're not at the AirASia end of DMK which can be bit of a ... zoo for passport control and security.
- Not squished together (even in the back)
- Arrives into KLIA rather than KLIA2 (not sure if there's any advantage)
What fare are you seeing? Seems DMK-KUL is priced a lot higher than the other way. I can get BC northbound for the price of EC southbound.