Pros
Working at REI was a great part time job - I got to talk to customers about their upcoming adventures and use my knowledge and experience to outfit them. It's nice that so many REI employees have a genuine interest in outdoor activities, and all have a sincere interest in giving great customer service. Pro deals and discounts are a great perk.
Cons
Having worked under 3 different store managers, the management style is different for each. One was excellent and really empowered employees to make the store awesome. One was more hands-off, but still fine. But the final manager I worked for didn't seem to put much effort into scheduling to make employees happy. Also, while I was not seeking to advance in the company, I had some coworkers who were passed up for advancement who I think would be excellent supervisors - again this likely has more to do with each individual store's leadership, and not company-wide policy. As a part time employee, compensation wasn't great, but it's a retail job. The pro deals and discounts make up for it if you're into outdoor activities.