The last coulple of weeks have been looking, online for a one way flight from Bangkok to Phnom Pehn. My flight from Clark get in lates, and wanted an early flight out in the morning, Air Asia departs at 3pm and Bangkok at 8am, so for an extra AUD40, Bangkok Air was worth it! Saving on taxi and hotels!
Went to book online last night and Bangkok Airlines now has a web advance 42 day fare, 55 Baht cheaper and with a meal than Air Asia, further searching show's BA is cheaper by 600Baht on a flight from Bangkok to CM.
So I booked Bangkok Airways.