Avantages
I can only comment on the various cloud operations teams since they're who I interacted with. For the most part, the people are great and know their stuff. There's a few folks who have been there since the company started, which speaks to a culture of retention. They also have a tendency to promote from within. I moved up through three different departments and during my time there and saw numerous other people get promoted up from the lower tier teams. The turnover in the cloud operations teams is so low that if anybody from those teams reads this, they'll probably be able to guess who I am, despite giving so little info.
Inconvénients
Applied Systems has been around for a very long time, so some of their software offerings are (understandably) based on older design ideas. You can gain a lot of experience and detailed understanding of Windows Server and all of its inner workings, but that experience may not be easily translatable to other companies as AWS, Azure, and GCP become more widely used.