I buy Zig runners twice a year.  At 280 lbs, jogging 8-10 miles per week, for the last 3 years, the soles compresses and need to be replaced in 6-8 month intervals.  I purchased this particular model in December and started using them in January, in March I noticed that a seam on my left shoe by the big toe had popped loose after one of my runs.  I have had other seams pop since.  I like Zig Tech because of the cushion it provides on my lower joints but this model quality disappoints.