I tried some more serious AI-assisted programming in my day job, yesterday. I had spent two days writing up a specification and describing the API. Then I wrote Gherkin for behavior tests with some AI help on the repetitive parts.
Once I had all that, I started turning GitHub Copilot loose on the problem.
With that tool, I made as much progress in a day as I might have made in several days without AI, but the mental exhaustion really start to set in after a while. There's so much code to read.
The tests are critical, and I defined a lot of test cases, so making sure those are correct will be the most tedious part. However, even when I said "go fix the code so the tests pass," Copilot started running in circles, copying a key file, then freaking out when all the duplicate definition errors broke the build.
So, it's pretty cool, but there was no "vibing" for the most part. I find I have to stay pretty sharp to make sure the LLM understands my intent.