My PBJ (24oz) and Samurai (22?) both frayed terribly at the creases on me. I personally have been gravitating less and less away from the ultra heavy fabrics just for personal preference but I've always felt it was a misleading opinion where heavy = long lasting. I've had heavy jeans disentigrate on me, I've had light weight jeans disentigrate on me and I've had both types last a while. It mostly comes down to the cotton and how the denim is loomed.
Iron Heart makes pretty uninteresting fabric but it lasts a super long time. They also use poly cotton thread on their stitches to make sure the thread doesn't evaporate like other Japanese repro jeans. But my 14oz Iron Hearts I've been wearing for 2 years straight now and outside of the typical issue of reinforcing the denim where my cell phone edges are they're perfect and not going anywhere using the same wash and wear pattern as all my other denim which fell apart.
Iron Heart makes pretty uninteresting fabric but it lasts a super long time. They also use poly cotton thread on their stitches to make sure the thread doesn't evaporate like other Japanese repro jeans. But my 14oz Iron Hearts I've been wearing for 2 years straight now and outside of the typical issue of reinforcing the denim where my cell phone edges are they're perfect and not going anywhere using the same wash and wear pattern as all my other denim which fell apart.