They changed the model ID we were using multiple times in the two weeks we had access to - so clearly they were still iterating on the model during that time.

They weren't deceptive about that - the new model IDs were clearly communicated - but with hindsight it did mean that those early impressions weren't an exact match for what was finally released.

My biggest miss was that I didn't pay attention to the ChatGPT router while I was previewing the models. I think a lot of the early disappointment in GPT-5 was caused by the router sending people to the weaker model.

For what it's worth, the GPT-5 I'm using today feels as impressive to me as the one I had during the preview. It's great at code and great at search, the two things I care most about.