Every day I do something where the llm writes it ten times faster than I would with twice the test coverage.

And every day I do something else where the LLM output is off enough that I end up spending the same amount of time on it as if I'd done it by hand. It wrote a nice race condition bug in a race I was trying to fix today, but it was pretty easy for me to spot at least.

And once a week or so I ask for something really ambitious that would save days or even weeks, but 90% of the time it's half-baked or goes in weird directions early and would leave the codebase a mess in a way that would make future changes trickier. These generally suggest that I don't understand the problem well enough yet.

But the interesting things are:

1) many of the things it saves 90% of the time on are saving 5+ hours

2) many of the things I have to rework only cost me 2+ hours

3) even the things that I throw away make it way faster to discover that 'oh, we don't understand this problem well enough yet to make the right decisions here yet' conclusion that it would be just starting out on that project without assistance

so I'm generally coming out well ahead.