Vantaggi
I worked in the US and in Australia and it was completely different. The Australian business is straight up awesome. Great people, solid leadership, good pay, the best projects, lots of opportunity for growth, a really cool office and benefits like health checks and wellness days. I'd give them 5 stars if I was rating the Australian office alone. There were a couple of bright sparks in the US - some awesome and smart people. There's a fair bit of movement between regions, far better than most international companies.
Svantaggi
The US business is a garbage fire. Poor leadership, no vision for the future of the company, promotions for terrible sociopathic leaders while the smart and collaborative people get overlooked. They talk the talk about having a great company culture but don't walk the walk like the Australian business. There is little respect for people's work-life balance. All the people I knew who had worked in both the US and Australian companies were extremely unhappy in the US. There's high turnover, all the good people leave and generally the poor ones stay.