Bottom line: I won't be flying with this airline again unless they stop charging insane fees for checked baggage.
Positives: The staff were all very nice and I think helped me out as much as they could given the situation with the airline policy/system, and the flight experience was all positive.
Negative: The charge for checked luggage is VERY high if you pay for it at the airport (I think if you are able to pay more than 3 hours before take off you can get the lower fee). They don't take cards at the airport (in Colombo at least) and you have to use cash that they recognize to pay this insane fee. For 15 kg it was about 50 USD, and that only covered me from Colombo to Bangkok, not to my final destination of Yangon. (They did give me the lower fee, around 20 USD, for that connection). The airline does not automatically include ANY checked baggage, even for international flights. And here's the most "interesting" part: if you try to check in online the day before, so you can get the lower fee, it does not work. If you tell them this at the airport there's nothing they can do and you have to pay the insane price.
Not sure if the airline is ripping people off intentionally or if they just can't find a way to make the online payment for baggage work, but I saw lots of people having this issue... and looking through reviews on here it seems like its an ongoing problem.
When you purchase a ticket, be sure you are OK with paying an insane baggage fee. Maybe the cost of your entire flight!