The interface is a bit ... hard to get used to, but makes sense after a while. Too many modes IMO, delete the "high" mode.
If you got to get to "High" mode, have to click it 3 times . If turned off, repeat it. Not a very good User Interface, and not all that practical.
I always run mine on Turbo and very rarely on "Low".
Not because I want Turbo, but because it's 1 (One) click to get to it. I don't want to click it twice or 3 times, so I often burn the cells more than I have to.
SOS and strobe are equally questionable, in real life you won't need them.
IMO it needs just 3 modes, low, med and Turbo.
IMO mode selection should be controlled by turning the head, and leaving it in a setting. and the on/off button should only turn on/off, forward 'tactical' clickie maybe.
This way if you like say "Medium", you can alwasy keep it in medium, or in Turbo.
I find that I switch modes very rarely, but you turn it on all the time.
Finally, the silly thing is very slipper - cannot believe they designed it like that.