For basic things like syntax that I can't remember it's actually pretty good, way more faster than google IMO.
When I ask for something a little more complicated it can go two ways:
Actually doing a good job and generating something that I can use (I often have to polish that code, but still, it's better than expected)
Doing whatever that I didn't ask for, so when I point out that's not what I meant and explain it further, it enters a bucle where it goes back to the two same solutions.
"You didn't like solution A? Here, there's solution B. Solution B is terrible? Here, there's A again."