I've seen this sentiment a few times before, and granted, I've never flown the Chinese carriers TPAC (in fact, moved heaven and earth so my partner could join me on DL instead of China Eastern on our recent China trip)....but...
....I did 3 China domestic flights, 2 on China Eastern in First and 1 short hop on China Southern in economy. I have to say I was really surprised by both hard and soft products and in fact, would rank it superior over any US domestic flights (for the slippers alone!) Food was good-great, service was attentive...there was a hint of smoke in the air on two out of the three flights, this is true, but after having had this experience, I would not hesitate to give them a try in J TPAC...