The iPhone 14 Pro Max is noticeably struggling with iOS 18.0 RC. I'm sure after a day, some of the setup tasks will complete but the phone is warm is opening apps is very slow. Looking forward to a 50% faster iPhone 16 Pro Max next week.

The typical reason I have slowness on all Apple devices is my photos library. If Apple makes photo improvements, my devices struggle for a few days as things get synced, indexed and trained.