Mixed
It probably still saved time compared to making all the changes myself. But it was way more frustrating
koreth1 on Hacker News
In the thread “1M context is now generally available for Opus 4.6 and Sonnet 4.6”, replying to this comment
Helped: Plan mode and initial review of a few files.
Got in the way: Incorrect variable placement and refusal to make simple fixes.
… Eventually I gave up trying to steer it and, with the help of another dev on my team, fixed up all the broken code by hand. It probably still saved time compared to making all the changes myself. But it was way more frustrating.