I'm mostly really enjoying it! While it's not my main job, I've always been a tool builder for teams I work on, so if I see a place where a little UI or utility would make people's life easier, I'd usually hack something together in a few hours and evolve it over time if people find it useful. That process is easily 10x faster than before.
My main work is training Text-to-Speech models, and the friction of experimenting with model features or ideas has dropped massively. If I want to add a new CFG implementation, or conditioning vector, 90% of the time Opus can one-shot it. It generally does a good job of making the model, inference and training changes simultaneously so everything plays nicely. Haven't had any major regressions or missed bugs yet, but we'll see!
The downside is reviewing shitty PRs where it's clear the engineer doesn't fully understand what they're doing, and just a general attitude of "I dunno, Claude suggested it" that's getting pretty exhausting.