I've flown Cebu Pacific heaps in int he Philippines - never had an issue.
You get what you pay for, but unlike the "low cost" carriers on Oz, they are actually low cost.
$75 Manila Cebu return.
Flown with them out of Kl to Manila as well.
Not sure about long haul. I have flown Air Asia X though, just get in early and pay for an exit or bulkhead row.