Have you noticed the most recent one, gemini-2.5-pro-0506, suddenly being a lot more sycophantic than gemini-2.5-pro-0325? I was using it to beta-read and improve a story (https://news.ycombinator.com/item?id=43998269), and when Google flipped the switch, suddenly 2.5 was burbling to me about how wonderful and rich it was and a smashing literary success and I could've sworn I was suddenly reading 4o output. Disconcerting. And the AI Studio web interface doesn't seem to let you switch back to -0325, either... (Admittedly, it's free.)