Just beat the whole game and very rarely changed out of my original outfit, half the time stealing another outfit will get you caught more then just wearing your original. Don't know how they could have overlooked this, but as of now not only are disguises mostly useless(unless you can find a very unique one) but the stupid instinct thing is useless as well.
I like to use disguises as a safety net when sneaking, but apart from that it's pretty awful. The idea is nice, but they detect you so fast it's just not fun to play around with. I'd be okay if they went into suspicious mode first or something, but most of the time they become openly hostile a few seconds after spotting you.