If you're somewhere in between (where I am now) it's situationally useful for small sub-components but you need to filter it heavily or you'll end up wasting a day or two going down a wrong rabbit-hole either because you don't know the domain well enough to tell when it's bullshitting or going down a wrong path, or don't know the domain well enough to use the right keyword to get it to cough up something useful. I've found domain knowledge essential for deciding when it's doing something obviously wrong instead of saying "I don't know" or "This is the wrong approach to the problem".

For the correct self-contained class or block of code, it is much faster to specify the requirements and go through a round or two of refinement than it is to write it myself. For the wrong block of code it's a complete waste of time. I've experienced both in the last few days.