I got subcontracted out from BCA to Lucky for 6 months and spend 4 of those in Kunming. For a secondary Chinese city, Kunming is OK. Air quality is good. Small expat section of town isn't bad. Schedules were 2-4 legs a day, 5-7 hours a day. Hainan group (includes Lucky Air) runs a slick operation.
Kunming is very windy and turbulent. I flew the bus in and out of Kunming and was happy for it. I am now flying the 737NG. If I was flying one out of Kunming I would get 4-8 flap overspeeds per day.
I never worked for West but they tried to recruit a few of us. They seemed clueless.
Given a choice between Lucky, BCA, Tianjin, West, and Hainan Air, I would choose BCA 1st, Tianjin or Lucky 2nd, West I am not sure where as I don't know much about it, and Hainan 99th. That was not a typo. Hainan would be 99th.
my two cents