The 401K has many advantages like:
1. The employee is permitted to give their share from salary under 401K plans with pre-tax condition so the amount of tax paid out of every paycheck.
2. In 401K the employer share is also important. The company gets benefits capital gain till withdrawal.
3. The employee can takes the decision where to shift investment give them control over the investment to the employee.
4. In case company go with your contributions; employee can gets extra benefits apart from the salary.
5. Employee and employer's contribution shift to other company's plan incase you change the service or you can also invest in IRA. It just as pension plan so it can be protected under the pension laws.
The 401K plans also have some disadvantages; it is hard to get your savings before 60 years. Under the 401K plans employer has no rights on the property. Employer contributions are not available to the employee till the defined years. IRS lay down limit on most of the 401K plans.