I was playing around with making a spiral with an equation driven curve, and then I noticed a couple of behaviors that leave much to be desired:
1. If you start a new part and create an equation driven curve, then add some other sketch entity and dimension it, the autoscale feature scales the equation driven curve so that it no longer follows the equations that you created. Tweaking numbers in the equation doesn't fix it, the arbitrary scaling is now permanently applied.
2. When you create an equation driven curve it is located relative to the origin, but then you can click and drag it (potentially by accident). Then as far as I can tell there is no way to move it back to the exact original position. Is there a way to "reset" the position of an equation driven curve?
It seems like in either of those situations you need to delete the curve and recreate it, which can be a pain if it is a complicated equation.