Although many people tend to think of being a perfectionist as a positive thing, true perfectionism is, in many ways, extremely counterproductive. Not only does the need to attend to every last little detail waste unnecessary time and lead to tasks and projects taking much longer than they need to, but it typically means that perfectionists end up allowing work to eat into their own personal leisure time. Perhaps worse still, even once the job is finally handed over, the perfectionist still never feels that he or she has completed it well enough and so is left with intense feelings of frustration and low self-esteem.
Striving for excellence is something that can only benefit ourselves and our employers, but there is a world of difference between this and trying to achieve the impossible. As human beings, we are not built to be perfect; trying to achieve perfection is a certain road to unhappiness. By all means give everything your best shot, but know when to stop because your best really is good enough!