Pros
REI has some of the best customers in the retail world- they want to be there talking to you and very rarely come in because they need someone to yell at. Other employees share your passions and are always up for getting together for a hike or a ride. Pro-deals are fantastic, as are the benis.
Cons
It gets really hard to drink the kool-aid there sometimes. Between management blatantly lying, never enough hours for the people who want them, and the absurd inability of the management team to agree on how to do things, it's frustrating to try and get hyped about explaining how awesome a company it is to customers every day. I have had weeks during the slow season where I wasn't even on the schedule- you never know week to week what kind of hours/money you'll get next week.