I haven't found the 'perfect' UI for my personal needs yet. And imo its not just a matter of how the light modes work, but everything about its operating. Things like the size/height of the switch, how easy they are to press, how easy it is to quickly change modes, how easy the switch is to locate in an emergency (in a tactical flashlight), the nature of the strobe (random flashes or regular) and how quickly its turned on when you try to activate it, etc, etc.
IMO the UI on the M series tactical Olights are outstanding and I own an M18 and M22 for that reason. Its not 'perfect', and there are a few things I would change if I could. I guess I would have to have a light built from the ground up for such personal perfection, but its as close as I have found for my requirements in a tactical flashlight, so far.