Interestingly though I don't get it to write code. It's no good at the language I write in, so useless there.
As a "tutor" though it's been really useful. I'm asking a lot of (probably simple) questions, and the answers are "right enough". Occasionally I'm not sure why something is failing, and it's usually helpful there too.
So, less brain-rot and more "helpful senior who helps me along".
[1] the work I'm doing is related to SQL, which I've used here and there before, but not to the depth or degree I am now. I don't need it to write SQL, but rather to answer more general questions and to compare SQL databases, discuss effeciency and so on.