Jess, nope, I only brought her on flight to HK last Dec, it was about 4 hours flight. For 1-2 hours, she napped on my lap and my legs were numb. Can't move her anywhere cos no extra seats for her mah.
After that, I had to feed her but luckily that time still BF so not so bad. If now, she is so easily distracted and starting to spit food everywhere. I think for coach ride, finger food like raisin bread or biscuits will be easier for kids.
Also on coach bus, usually no toilet (even if they have, most of the time, they don't open it) so diaper changing will be messy if they poo. If wee wee, still not so bad. Even if they have toilet breaks at Yong Peng, the toilets are not very clean and usually wet.
If budget is not an issue, maybe buy a seat for him on the coach bus? So that both of you will be more comfortable especially since they may fall asleep on the coach.
Told hubby I want to go to Penang with RaeAnne and no. 2 again, at least it's only 1 hour flight, no need to prepare so much things, and Airasia flies in the morning and when we arrive, can check into hotel liao. Just nice.