Ventajas
There are opportunities for internal promotions. No one really stays in the same position three, or four years unless they want to. Taking PTO when needed was never an issue. Upper Management was really good when I was there.
Desventajas
You will work a lot. There were many times I had to join meetings with clients on other continents, so many days could start very early in the morning, or end very late at night. The raises in salary where surprising small, because they preferred to give large bonuses, which I didn't really like. I don't think this is true across SAP in general, but it was where I worked. I really need to mention that my team interfaced with a lot of other teams, so we were really busy. Multiple members of the team made the case that headcount needed to increase, but it never really happened as often as it should.