Pros
Everyone from the top to the bottom genuinely cares first and foremost about making great games. No shovelware here, no publishers dictating design to try and catch the latest fad. Great products, successful company, I've had maybe 2 days of crunch in 4 years. It seems like every week we are celebrating someones 10, 15 or 20 years here at Blizzard. People tend to join and never leave. Art, design, and other creative fields are respected much more here compared to other companies (I'm an engineer FWIW). I've seen several problems come up which would be company sinking crises at other studios (I've worked at 7 other game studios, and have seen many layoffs and shutdowns), but here, the ship changed course, smart decisions were made and implemented, and disasters were averted. Pretty amazing.
Cons
The fact that Blizzard has such good employee retention means there are a lot of people with 10,15,20 years of experience who have never worked anywhere else. IMO "fresh blood" from the outside would be helpful to get some things up to modern industry standards.