I also have had the same experience. The sole wearing down is quick but it stays grippy. In comparison to other shoes, the shoes overall tread lasted longer, but once it was gone the shoes felt like ice skates. Converse in particular were the worst offenders of this, followed by vans. I will say tho, the last resorts did lose some grip once the sole wore away, but they were still good enough. Also the wear on the tread was quick, but the bottoms still lasted me a month before they got too thin for me.