Matches my experience too. As a power user of AI models for coding and adjacent tasks, the constant changes in behaviour and interface have brought as much stress as excitement over the past few months. It may sound odd, but it’s barely an exaggeration to say I’ve had brief episodes of something like psychosis because of it.
For me, the “watering down” began with Sonnet 4 and GPT-4o.
I think we were at peak capability when we had:
- Sonnet 3.7 (with thinking) – best all-purpose model for code and reasoning
- Sonnet 3.5 – unmatched at pattern matching
- GPT-4 – most versatile overall
- GPT-4.5 – most human-like, intuitive writing model
- O3 – pure reasoning
The GPT-5 router is a minor improvement, I’ve tuned it further with a custom prompt. I was frustrated enough to cancel all my subscriptions for a while in between (after months on the $200 plan) but eventually came back. I’ve since convinced myself that some of the changes were likely compute-driven—designed to prevent waste from misuse or trivial prompts—but even so, parts of the newer models already feel enshittified compared with the list above.
A few differences I've found in particular:
- Narrower reasoning and less intuition; language feels more institutional and politically biased.
- Weaker grasp of non-idiomatic English.
- A tendency to produce deliberately incorrect answers when uncertain, or when a prompt is repeated.
- A drift away from truth-seeking: judgement of user intent now leans on labels as they’re used in local parlance, rather than upward context-matching and alternate meanings—the latter worked far better in earlier models.
- A new fondness for flowery adjectives. Sonnet 3.7 never told me my code was “production-ready” or “beautiful.” Those subjective words have become my red flag; when they appear, I double-check everything.
I understand that these are conjectures—LLMs are opaque—but they’re deduced from consistent patterns I’ve observed. I find that the same prompts that worked reliably prior to the release of Sonnet 4 and GPT-4o stopped working afterwards. Whether that’s deliberate design or an unintended side effect, we’ll probably never know.