Paying yourself: the difference between an owner who withdraws and an owner who is paid a salary
In a sole trader business you 'withdraw'. In an ApS you are employed by your own company. That changes tax, pension and what the bank sees.

Sole trader: you withdraw
There is no salary. The profit is yours, and you are taxed on the whole profit whether you transfer it to your private account or not. What you transfer is called a private withdrawal and is booked as such, not as an expense. So it affects neither the profit nor the tax.
Consequence: set money aside for B-tax, and don't let the business account be your wallet.
ApS: you are an employee
The company is the employer, you are the employee. Your salary is an expense for the company (and lowers the company's tax), and you pay A-tax on it like any other employee. That requires the company to be registered as an employer, run payroll every month and report to eIndkomst.
Salary or dividend?
Profit left after your salary is taxed at the corporate rate (22 %). If you take it out as dividend, you are taxed again (27 % up to the progression threshold, 42 % above). Salary is taxed only once, but at your personal withholding rate. The right mix depends on how much you earn and what you want to save; a question for your accountant once a year, not something to calculate every month.
Three things that are the same for both
- Pension is your responsibility. Nobody pays in if you don't.
- Parental leave, sickness and unemployment benefits require that you have joined the schemes; check before you need them.
- The bank assesses your finances from what is in the accounts, not from what you "usually take out".
What LegaSum does
In a sole trader business LegaSum records your withdrawals correctly and shows the real profit next to them. In an ApS the plan makes sure the company is registered as an employer and that payroll runs, and the salary/dividend question is asked as one question as the year draws to a close.