I flew LAX
in their premium Y last March and return in standard Y. The food is exactly the same as in standard Y, it's just served in real dishes instead of plastic. There were 3 full meal services plus snacks whenever one wanted. IFE was on demand and had a decent amount of variety to please most people. I found that the flight (17.5 hours) went by rather fast, all things considered. The return to JFK
was the same and as I said, in standard Y, in a middle seat with the one next to me open. I think the standard Y was more comfortable... based on the position of the leg rest and the fact I could move the arm rest. THe staff was nice, even at the end of the flight, though they seemed sort of detached and robotic at times. NO shortage of the wonder Thai smiles though!
Have a great trip... it's the best way to BKK