Pros
You have the chance to work on high profile projects for well known clients in great locations. From a technical design perspective, there are some of the world's best experts working in the planning and facade departments. Seek these people out and learn as much from them as you can; they are truly amazing.
Cons
During COVID, SOM will announce a policy of no raises and promotions for labourers and below. They will lay off 15% of the staff and increase the workload for labourers. However, management will continue to receive promotions, raises, and bonuses. Profits will still be drawn for the partners. In the next breath, leadership will state the importance of "equity" in workplace culture. When you get hired, you will be told there is no distinction between "design" and "technical" departments. However, there are design teams led by design managers and technical teams led by technical managers. Designers will never do construction administration and technical people will typically never do anything before DD. Designers will use Rhino/Photoshop/Illustrator and technical people will only use Revit and bluebeam. It is extremely difficult if not impossible to transition between these roles. If you ever ask a manager about these differences, they will say there is no difference between technical and design departments.