Pros
Some very smart and talented people, especially at the junior and mid-level, though most of those people are leaving in droves. Dog friendly offices, amazing employer branding, though it's mostly a facade. Work life balance for some is great, others not so much. Really varies by team/department. Historically a strong agency, but that is swiftly changing.
Cons
Huge is an operational disaster. Executive team are all incredibly immature and have no idea how to run a global business. They've formed an impenetrable clique of the old guard and bully the rest of the agency, including the executive talent they hire and fire at a whim. Egos are out of control and leadership don't acknowledge their faults. Nothing this company does is proactive or strategic, everything is reactionary and haphazard, including laying off Huge swaths of the workforce and closing offices frequently, only to realize they don't have the talent to deliver work the next week. The one thing they are good at is minimizing media attention to these layoffs, though in truth the company lost about 1/3 of its workforce in 2017 alone. The work is suffering massively. It's all about $ at this point, so the company will take on tons of boring accounts just to keep the lights on. Huge fumbles on delivery frequently and many clients are pulling their business altogether from the agency.