I had a great run with iOS 18 betas myself, but to be fair I use Superhuman and sometimes Spark for email - so Mail was avoided, and just glanced at =)
Siri is absolutely terrible, but that's been the case for years. I use LLMs quite a bit, and I sure hope Apple doesn't end up digging their heads further into the ground over the future interfacing necessary to really have AI feel fantastic (watching the io buyout/merge carefully, but I think the lasting solution is a family of new approach OSs across all screens and audio devices - not just a gadget) - with local only and cloud assist by option common sense
I'm looking forward to Jony's upcoming reveal and iOS 19 and all her beautiful blunders! haha, but yah - the complaints over iOS 18 beta development are kinda wild, ths OS is fine.. and the largest problem remains: Apple missed the wave break of AI/LLM to surf just yet, and that's pretty bad for a company with so much talent in their mother-ship