Pros
I made a lot of friends, and my first 6 months in the company were fantastic. In general it's a positive and friendly place to work if the management are good. Decathlon is a very transparent company. Profit sharing and bonus schemes are good. Great discount on Decathlon products. I had the pleasure of working for the best manager I've ever had, too bad she moved to another store. There are plenty of opportunity to progress, but only in store related management roles, not really to other areas of the company.
Cons
All too easy to end up with terrible management that make life miserable. Upper management make up new roles for people who suck up to them enough, or they just promote them to management positions. No regard to whether they'll be any good at those roles, they just like having yes men around that have no regard for anyone other than themselves. I'm all for people progressing their careers, but not if they trample on others to do so. It means you end up with some management who treat shop floor staff like crap and just sit in the office for nearly their entire working week and aren't part of the team. Then they wonder why staff are unhappy. I dropped from 5 days to 4 because the stress was really getting to me.