It's surprisingly good but you have to have a bit of "theory of mind" to get what and why it can do graphical manipulations. Somehow Claude can draw 3D object wireframes but struggles to know where to draw the leader for a label in a diagram.

Also funny you should say you're too slow at 3D modeling but interested in using LLMs to do it. I'm on the other end. Not speed demon, but generally it's a lot faster to generate the geometry myself than to try to describe it. There's a lot of "how you got there" stuff that matters a ton for parametric modeling. If you want a CAD model that can easily be worked with you have got to be a bit smart about it, and I am not sure I see LLMs having that kind of spatial intelligence + deep physical world context soon. For one thing, it's a lot harder to do RL on.