My experience with smaller models, in this case specifically GPT 5.4 Mini, is that they cannot two-shot moving a 10-20 line code change to another file without modifying it and introducing bugs.

I did not expect perfect reliability, but I thought they could at least get it right on the second attempt once you point out the difference. No such luck, it confidently tells you that now the code is the same, with yet another subtle bug added in the difference.

I don't know what work one would need to do where these garbage-class models would be adequate. Maybe they can masquerade as competent for a few minutes, but in the end the results simply are not right. At best they are suitable for a smarter search or autocomplete, in my opinion.

I use Gemma 4 26B A4B on my Macbook (M4 Pro, 48 GB RAM) to study Rust (and ask other myriad questions). I don't trust it to do a good job in an IDE/harness to one-shot anything but the most trivial of changes. Still, it's fast and good enough that it could handle being a "co-pilot" on small to medium context tasks where you've got your hands on the wheel and your eyes on the road — and are driving under the speed limit. That's remarkable given where we were a couple of years ago.

I don't think I'd be using AI to code at all if this weren't the case. (I don't want to feel stunted or stuck just from losing my internet connection.)