Perfectionist takes exactly what I really don't need and see no point in a Splinter Cell game, but however, even after with all of these "features" off, after looking in this video, the detection system of your enemies that spots you is way to sensitive and that bothers me a lot, force me or giving me some restrictions to take him out only through few ways, like running around to get behind him all the time, always could make the mission a failer cause who knows how fast that dectection starts and when. Who knows how many times I have to repeat that to succeed.
It was much nicer and funny back then when the guardian was passing by through a corridor and you were hiding in the dark, leaning on one of side of the wall.
For the detection system, I remember in first Splinter Cell when any guardian who has seen you in the light was saying first "Who's there ?" and then approaching towards in step-by-step silence just to verify "something is there".
At least here, is enough to just see me and start shooting. They are always in the look out on you.