Pros
Management from the top down are generally excellent engineers in their own right, and there is no 'chain of communication' requiring you to go through anyone to contact anyone else about any issue. The vast majority of engineers at the company are very highly skilled and also eager to help anytime it's needed, and this is encouraged by the company culture. Speaking up is encouraged and rank is almost never pulled. A junior engineer can disagree with a lead and will be listened to. Good ideas will get pushed forward and taking initiative on projects tends to be rewarded. Credit is given where due and there's no glory stealing or corporate politics that you often see at other companies.
Cons
The highly collaborative culture sometimes means that there is no one owner or decision maker for a system or issue; this can lead to decision paralysis and meetings with multiple stakeholders who can't agree and therefore prevent any progress. This is getting better, but it's still an issue.