Overall, I personally think Thai Airways is OK. Aircrafts are comfortable, good meals and on-time rate is high.
However, I don’t think their customer service is good. Some of the flight attendents are not friendly enough. I remembered borrowing a pen from one of them to fill in the immigration form. I
had to ask for the pen for 3-4 times (lost count) before they got me the pen. The air stewardess who got me the pen showed me her “unhappy face”. Also, another time, after a while the aircraft landed, it was still moving slowly for parking but some of the passengers ...