I actually had a really impressive session with Fable last night, probably the most impressive agentic AI experience in a while.

I gave it a KiCad schematic of a tube-based oscilloscope from the 60s which I'm restoring. I had it give me a breakdown and priority list of components to replace, balancing safety/functionality vs preserving the originals. Then we went on a super deep dive where it explained in great detail how the circuit works and what the tubes are doing.

It isn't so impressive that it could explain vacuum tube physics and circuit theory, but it was pretty impressive that it could consume four pages of KiCad schematic and reconstruct the full topology and theory of operation with no additional information. I was able to ask it questions about what a particular tube or group of components did, or how this system interacts with that one, or what the risks and benefits of this design choice or upgrade might be. Very fluid, and its answers were actually really smart.

I have, however, found Fable to be far less impressive on coding tasks.