You need not set the pads in very close, and it may not even be advisable for you to do that while you get used to discs. However, you don't want to set them so wide as to almost run out of cable before the brake engages since cables do "stretch";you don't want to be caught with too much cable and too little "pull" out on the trail (or anywhere else!) Yes, there are adjusters so this problem can be 'fixed' on the "fly", but the time that a "problem" is paid attention to is all too often the time the "fix" should have been made several miles beforehand...