Depends on the context -- do you mean Gemini CLI for coding or Gemini the chat web app?

For the CLI -- no, I have not noticed and hallucinations.

For the chat app -- no, and the more I use it, the more it feels like its getting better with time.

(I pay for the $20 plan btw)

For me it started degrading in December and then fell off a cliff a couple of days ago. It's nowhere as useful as it was just mid Q4 last year.

If you mean in coding context, then yes it went down pretty bad to what it used to be back in December.

I’ve using paid AntiGravity and it was brilliant back in December, similar quality to Sonnet 4.

But it’s been degrading in the last 2 weeks. Now I either use Sonnet in anti gravity or Codex.