I looked at these when I had the KR2 and I understood the cheaper one to simply show range and altitude, it didn't give you a quadrant in which to search...
The more exxy one gives you a quadrant (out of 8 I believe) plus range and altitude to maximise your chance of seeing the other traffic.
Of course, that only works if he's got a transponder, it's on Mode C and his encoder is accurate...