They're awful and hallucinate a lot, I couldn't imagine using it even for prompts about TV shows, even less so for serious work. Repeating the question from the parent, have you tried those yourself? Even compared to ChatGPT Thinking, they're short of useless.

They're essentially replying based on vibes, instead of grounding their responses in extensive web searches, which is what the paid models/configurations generally do. This makes them wrong more often than they're right for anything but the most trivial requests that can be easily responded to out of memorized training data.

This is all on top of the (to me) insufferable tone of the non-thinking models, but that might well be how most users prefer to be talked to, and whether that's how these models should accordingly talk is a much more nuanced question.

Regardless of that, everybody deserves correct answers, even users on the free tier. If this makes the free tier uneconomical to serve for hours on end per user per day, then I'd much rather they limit the number of turns than dial down the quality like that.