As a perfectionist, I need to line things up perfectly. Thus far I have had to resort to creating rectangles and stretching them across the artboard so that I can align precisely. I am aware that you can make the grid smaller - but this can only be done down to 25 pixels and you cannot move the grid around to aid alignment.
It would be very very helpful to have rulers you can click, drag, turn on/off (much like those you can find it Photoshop/Illustrator/InDesign). Please consider adding these!