Pros
The best group of folks I have ever had the pleasure of working with, and I've been doing the software gig for a long time. Everyone, from summer college interns to senior crew have insightful, relevant perspectives to offer to anyone willing to ask. I know that I can go to _anyone_ at Riot, President on down, with a question, off the wall idea, or concern and get a thoughtful non-bullcrap response from them. I cannot stress how awesome and valuable this is. Riot is fantastic at promoting personal growth. If you get hired in a position but decide you might be a better fit or happier elsewhere in the org, they go above and beyond to help you transition and succeed.
Cons
Not much to say here. Prior to Riot, I worked with firms where downtime or interruptions more than a couple seconds long would lead to Very Bad Things. Sometimes we identify player-impacting problems with straightforward solutions that take, in my opinion, too much time to implement.