The AI Models Index keeps tabs on premium releases from 15 labs since 2023,...

https://reidyxab469.iamarrows.com/is-gpt-5-2-actually-worse-than-gpt-5-1-in-blind-votes

The AI Models Index keeps tabs on premium releases from 15 labs since 2023, with verified dates and blind-vote checks to ensure accuracy. Updated every two weeks, it shows new models drop every 4.5 days on average—a 56% improvement rate