I often use de Pen Tool for creating a path that helps me select the area in a layer. After I've created the path I press Ctrl + click the path layer thumbnail and there I have it, a sharp and smooth selection, and then I delete the path. You already know, the Pen Tool is very helpful for this because every point you have the option to make a curve or line etc. and also undo a point... VS the options of the Lasso Tool, I use them a lot but doesn't have that capacity and flexibility. So.. I know it will be great and fun to use a Pen Lasso Tool, a Lasso Tool that you can make points in which you create curves, lines and even undo steps. I think that if it is a new Idea its worth a shot.