My problem with G6 is it's LG UX software. It's pretty inferiror to Samsung Experience. I feel like I am using the old TouchWiz when I use G6 with respect to it's UX. The LG SmartWorld app is too slow and the themes are also not good. Of course you can download other launchers to theme but comparing this with Samsung Themes, LG Themes are very bad (so are HTC Themes).
My next problem with G6 is lack of shortcuts, especially camera launch shortcut. Every phone has the standard shortcut - double press the power button - to launch camera at anytime and support one or more features in the FPS. G6 lacks both. AOD too is inferiror to Samsung AOD where you can apply lots of themes and take actions on the icons that take you directly to the app.
I am not being negative but I have the S8, G6, U11, OP5 and Honor, and, G6 is my least favorite.
For a flagship phone, if they had put more effort in the LG UX to be more memorable!