Their is a bit of contradiction among CS and Mechanical, always and everywhere.
Let me give you some points for discussion:
- Salary : First package, After 10 Years and At retirement time.
- Quality of Life
- Working Areas
- WorkLoad
- Responsibility
- Job security
- Age to Career Options
- After Retirement Options
You might want to think about these points before going for scope of any branch.
These days CS students get a bit higher packages as compared to any other branch of engineering, true and must be, because the technology shift in CS always requires some freshers who can mold with the cavity. Now, consider this parameter from another side of coin, you will think that what will happen if the technology shift will affect on persons who were working on previous technology. They lose their jobs.