Lessons: Linux & GTK+ are terrible, hardware guys making decisions without design & software direction are terrible, open doesn't help if you run a shitty stack. I ♥️ Python, but not in a kernel.
That puck phone was the ugliest thing in the world, and it couldn't reliably make or receive phone calls, which in 2007 would've been feature #1 in a phone.
The design mockups are hilarious, Photoshop without any connection to shippable code.
And the Commodore PET sucked.