Actually I like the disguise system.
It makes sense that if you are dressed as a cop and you get to close to another cop he will recognize that you are not one of his team, especially since they are actually looking for you.
I mean think about it, if someone went into your place of work wearing your uniform and it was someone you didn't recognise and he was bald with a bar code in the back of his head don't you think you would notice?