I have found that when I fill the forms out honestly and accurately, it results in too much tax being withheld. It is certainly true that I can fudge the forms

I have found that when I fill the forms out honestly and accurately, it results in too much tax being withheld. It is certainly true that I can fudge the forms to get a more accurate withholding (and I have done that at times), but it does seem to withhold too much by default.