I use EQ4 to draw pictures of the quilts I am designing - it's particularly helpful for telling me how big my quilt is without having to do that math over and over as I play with borders, sashings, changing the block size, etc. and also for printing out pictures for reference. I also like it for gauging values and contrasts. But for actually drafting a pattern or drawing pictures of the step-by-step process, I usually use AutoSketch - a light version of AutoCad - and do the math by hand for cutting instructions and yardage.