I used to like controllers more, then i started playing on PC more

The fact is that vibration does not make up for the lack of immersion that arises from not having true control of your character. If i want to turn a 180 using the mouse, i can, with a controller i slowly (relatively) wheel around like i've got some crippling mobility disease. Also, increasing sensitivity doesn't help because then you aim like you have a nervous twitchy arm.
Controllers are just not very good for first person shooters, and are far less comfortable too. If you think your kb+m combo is uncomfortable, then you're doing something wrong (or have bought something wrong, like a terrible chair, terrible keyboard, terrible mouse ect.)
