So the last few days I've been trying out different sensitivities and DPIs settings.

The most notable ones are :

(1) 400dpi sens 4 = 26cm/360
(2) 3200dpi sens 7 = 1.9cm/360

(1) feels good, especially at long range and with "straight rocket aim". You have to move your hand/arm a lot, actually it's quite nice when you get used to it. But imho if someone moves in circle around you, it's hard to keep track of the target. And sometimes you end up in an uncomfortable hand position on the mousepad. Actually you have to make quite a lot of effort to follow the long/med strafes. I would say this kind of sens requieres you to be in shape, to not be sleepy or anything, and you need to play a lot to get used to it.
I like this setting, but imho not optimal. I can still find quite obvious flaws when I play with it.

(2) yes, I know, it's MADNESS. Most people will be like "WTF did he just try ?! Insanely high sens !". In fact, it's not as bad as people might think. When you play for more than 1 hour with it, you start to understand how this kind of sens works. You never move your arm, only your hand/fingers/wrist. When you start to calm down and you start to control every micro movements, it's fine. Obviously my overall accuracy dropped a bit, but I think that it was mainly because I probably would need at least 4-5 days to get used at almost 100% to an extreme high sens like this one rather than this kind of mouse settings being just bad.
Now I understand a bit more how agent can be so good with ~5cm/360.

I won't try anything that is slower than 30cm/360, because imho low/ultra low sens is overrated.

Then I went back to my usual 1600dpi 11.3cm/360, and you know what ? I almost felt instantly at home lol. I remember when I switched from 23.1cm to 11.3cm, it took me like only 2-3 days to get used to it at almost 100%. I think there's something "magical" with 10-15cm, it's high, but not ULTRA high, you still have to move your arm sometimes, and unlike with 25-30cm, you can track better the target in some situations without having an uncomfortable position on the mousepad. Ihmo this kind of sens has almost no weakness(es), but you have to try it yourself to understand.

:)