Earlier quoted context omitted.
If it works like the 3419W you have one button press to wake the OSD and then a press on the input you want to switch to. Not terrible, not great either because on the 3419 the OSD is a bit slow and the button are below the screen so you can’t reliable double click to switch.
If you ever try using the KVM feature on for instance a Phillips monitor, you'll realize the Dell feature is a dream!
And that sometimes it’ll get confused and won’t switch the USB peripherals correctly, but that’s not too common (hasn’t happened in a long while in fact, maybe there was a firmware update I didn’t notice which fixed it).