I am so concerned about all the other work that has to be done that I tend to fall on the other side of the spectrum; get the design to an 'acceptable' place and move on.

My attitude is something along the lines of 'If you're not freaking out, you're not working hard enough'

That said, I still havent launched publically, mostly because of all the 'details' of which you speak (core product works but is ugly).