hi
i have been putting looking at the hole almost a year now, at first i felt the long putts seem to be closer to the hole than before. now i feel relaxed on all my puts and feel i see the line better looking at the hole than at the ball. i feel i can't miss from 6 feet in and my puttng has improved lots. i did also change my putter to a broomhanded putter a year ago too.
i do think you have to play looking at the hole for a month or two and not just a few pratice shots on the green.
bill