Pros
Only place I've ever worked where it truly feels like every voice is being heard and considered on some level, regardless of position or seniority. Riot is making a sincere and concerted effort to address the reported, and very serious, negatives. I get to work with some of the best and brightest talent in the industry and show up to a place that feels like it truly values me. Employees are encouraged to take time off for any number of reasons to make sure and maintain a healthy work/life balance. Additionally, the open culture encourages you to make time to meet and build relationships with people that you may never cross paths with otherwise. Of course there are also the excellent perks of unlimited pto, full cafeteria and coffee bar (at LAX at least), as well as all the other cool things you can find in any number of published articles.
Cons
Riot grew really large really fast and is having to deal with the consequences of success. This can lead to some breakdowns in structure and communication that may have worked at 300 employees but does not scale to 3,000.