What it does offer for me, in practice, is basically "clever autocomplete". Say I wrote a little bit of code:
bounds.max.x = bounds.min.x + width
Then copilot will suggest that the next line is: bounds.max.y = bounds.min.y + height
That's reasonably smart, and it adapts pretty well to whatever code you are currently writing. It makes writing those little bits of slightly repetitive code less annoying, and I like that – it feels like a useful productivity boost in the same way as regular "dumb" autocomplete is.However I'd say too much of the initial coverage was along the lines of "you can just write the function name and it will fill in the body!". That will work if you want to write `isEven` or `capitalise` or something, which again is quite nice. But I have found that basically any other prompts product a function that either does something completely wrong, or introduces a subtle and non-obvious bug. And this actually feels kind of dangerous – I'd absolutely caught myself a few times from just going "it'll probably be fine" and accepting whatever Copilot has spewed out.
I'll remain sceptical of it as a system that sucks up and regurgitates vast lakes of open-source code and sends my every keystroke to Microsoft, among other things. But it's definitely something I'd pay for a local version of.