The difference between Ubuntu and the two variants you mentioned is solely on the application layer and as long as they don't use the buggy KDE5 connection manager applet, WiFi won't be affected by Xubuntu or Lubuntu. So this boils down to preferences of desktop environments. I've always wondered why, instead of full distros, these variants weren't just supported more officially as flavors to choose or change to. Yes, you can install lubuntu-desktop from inside a stock Ubuntu install, but there's always some configuration and setup that's missing.
Well, the OS I'm running is Ubuntu, and Kylin is "Ubuntu for China", with fcitx set up for Chinese already, and a separate Software Center that has a delightful page that shows Linux alternatives for Windows software. Haven't quite gotten around to playing with other linux distros to be honest.
Interesting. The Chinese devs I work with hate Kylin (probably because it's approved by the Party) and seem to really prefer other Chinese-created variants, particularly Lubuntu and Xubuntu. I've got no experience with Kylin, so it's interesting to hear these points.