Interesting. When I ran my S Corp, my goal was to avoid estimated tax payments. At the end of the year, the accountant would calculate the required taxes and I would issue a "net zero" check that only paid taxes, or a bonus check with a enormous withholding. The remainder was taken out as a dividend.

Taxes paid via withholding are treated as if they are paid in through the course of the year which avoids estimated tax payment penalties.