Excellent, worked right out of the gate. Like all of Waveshare's stuff, the documentation mainly consists of sample Python code, but as long as you can read and decipher that - not much of a chore - it works great. One note that's not immediately obvious from the docs, but very welcome - when you power the Pico off USB, it provides the shield with power as well, so you don't necessarily immediately need another voltage source for your motors. This is great for quick testing - my little four wheel robot runs much slower with 3.3v USB provided power than with a 9v connected directly to the shield, but if you just need to make sure everything is wired up properly, it's wonderful.