I feel like the value of my plus subscription went down when they released GPT-5, it feels like a downgrade from o3. But of course OpenAI being not open, there is no way for me to know now.

Likewise.

I'll play devil's advocate and say that I think the Codex-cli included with the plus subscription is pretty good (quality wise). However, after using it, it suddenly told me I couldn't use it for a week out without warning. Claude is a bit more reasonable there.