I have been quilting for 50 years or so and consequently have many rulers already...too many to spend money on replacements.... so when I saw the block lock rulers... I laid out a line of 5 layers of masking tape.... stuck to my big cutting mat... then I used a stable ruler to hold and cut a perfectly straight line... then i repeated approx 3/8" away from first cut. Removed from table..applied to the bottom of a ruler with excess over both diagonal corners... I trimmed them with a rotary cutter...flipped the ruler over and have been using for a year or so... I honestly don't think it is any faster or more stabile.. to the point that I have not altered any others... to each his own... i don't think they're wrong or anything .. but not for me.