Pros
The people (fellow employees) - Everyone learns from each other and there is an ability to form friendships that reach outside of work hours. Good benefits (401k matching - automatic 4% regardless of whether you make a contribution, plus 75% of your contribution up to 4% of compensation, health, dental, vision)
Kontras
Senior management incompetence - There are too many horror stories to list, from management not giving employees any bonus so they'll leave instead of management just laying them off, to laying people off on a Monday morning after they spent the entire weekend in the office to finish a project, to unfairly discipling people, so UBS can show statistics of how they handle situations. Lower compensation relative to peers - $5-10k less for each employee here and there means senior mangement can pad their own pockets.