I am an old coot, took drafting and mechanical drawing in the 60's, and studied architecture in the early '70's, when it was all pencil and vellum work. I remember being wowed by the first totally unaffordable HP electronic calculators, gee whiz! Anyway, I have tried multiple times to learn and use CAD, but find I get too caught up in the nuts and bolts of it to actually give my best efforts to the object itself. I am good at thinking spatially and doing most of the math in my head, so a simple quick sketch on a scrap of paper usually gets the project moving along. I do not find the old school approach limiting at all, rather enabling, but my history definitely plays into it. Of course, I only take on projects that fit my current tools and skills...