I actually have the predecessor to this shoe, the Techsun II, and am very disappointed.  I have had them a couple of years, but haven't worn them that much (as evidenced by the lack of wear on the sole).  However, the front portion of the sole of one sandal has separated from the body of the sandal, rendering them useless unless repaired.  Based on this, I would be very leery of buying these.  I have had other Columbia shoes that have held up very well, so this may be an anomaly, but I'm not happy at having to absorb the cost of the anomaly.