International flights of Xiamen Airlines. How are they?

To be fair, I have taken Xiamen Airlines four times so far, usually during the summer vacation, so I chose a discounted economy class ticket, but I didn't feel the service quality decline because of this. I haven't taken Xiamen Airlines international flight, but I think it must be very good. After all, international routes are a window to the external image of airlines, so since international flights are done well, international flights should be good. There are not many international flights of Xiamen Airlines, which are usually from several neighboring countries.