The main upside of going down the company route is the pension angle.
A sole trader can only contribute a fixed percentage of their income to a pension scheme based on their age and a maximum notional salary of €115,000.
Take someone who's 52...he or she can only contribute €40,250 to a pension if he or she is a sole trader or an employee.
But a company can contribute an unlimited amount to its employees pension scheme (subject to the €2.3 million fund cap).
With these one man band companies, no corporation tax or close service company surcharge should ever arise because any surplus at the end of the year should be just lashed out in a combination of salary and pension contributions.