The only thing I've returned to REI in 40 years was a travel toothbrush, 30 years ago, that melted in my glovebox in the car. The clerk told me that I shouldn't have left it in a hot location. I still had the packaging and pointed out that it said nothing about any storage temperature limits. It seemed pretty petty on a $4.95 item, which the clerk did eventually replace (Berkeley store).
I was impressed the first time I was at REI as a 15-year-old Boy Scout thinking I needed really heavy, expensive boots for a week-long backpacking trip. The guy in the shoe department suggested a lighter, less expensive (but still heavy) Raichle boot and it impressed me that he suggested the less expensive item. Much later, I realized that the salespeople weren't on commission.
I still like the cooperative model. I like the 10% back each year.
I don't like that there are no real democratic elections in the cooperative. When was the last time you saw a contrary candidate running for the board? That is likely contrary to IRS regulations for cooperative (says the electric cooperative Director). Only board-nominated candidates are put before the membership, and they are high-level finance and legal types, which yes, keep them on a even keel and financially solvent, but also risks not engaging and targeting typical members.
There was a time when they gave the weights of all gear. They longer do.
While they still are primarily about muscle-powered sports, they do sell alpine skis which 99.92% of skiers use on 500-hp ski lifts - hardly a muscle-powered activity.