Presently, it's the best we have from the PDGA. Walking it off is likely even less accurate. Since one's cardmates may be irritated by the question and refuse to assist, I intend to buy and use one of the cheapies. If I'm so close to C1 that it's a squirrelly thing still, then I'll do a regular putt. If the rangefinder says I'm distinctly out (say, 42 feet), then I shall step putt. I find the step putt incredibly useful for a controlled, long layup. If there's no paint or whiskers, I'm not able to ascertain the difference between 30, 35, 40 feet at every green.