5.2 is back to being a sycophantic hallucinating mess for most use cases - I've anecdotally caught it out on many of the sessions I've had where it apologizes "You're absolutely right... that used to be the case but as of the latest version as you pointed out, it no longer is." when it never existed in the first place. It's just not good.

On the other hand - 5.0-nano has been great for fast (and cheap) quick requests and there doesn't seem to be a viable alternative today if they're sunsetting 5.0 models.

I really don't know how they're measuring improvements in the model since things seem to have been getting progressively worse with each release since 4o/o4 - Gemini and Opus still show the occasional hallucination or lack of grounding but both readily spend time fact-checking/searching before making an educated guess.

I've had chatgpt blatantly lie to me and say there are several community posts and reddit threads about an issue then after failing to find that, asked it where it found those and it flat out said "oh yeah it looks like those don't exist"